What was going on when I was born?

International As the marines arrived in Beirut, statements by President Reagan and other Administration officials left uncertainty about the precise nature of the marines' mission and how long they would stay. Mr. Reagan told Congress the marines would be in Beirut ''only for a limited period.'' But later he said they would leave Beirut only when the Lebanese authorities said they themselves could insure the nation's security. (Page A1, Column 6.) The marines landed by ship and helicopter and took control of the Beirut International Airport minutes after the last Israeli soldiers withdrew from the area. About 800 marines arrived yesterday, and 400 more are expected today, joining the French and Italian contingents of about 1,100 men each that make up the multinational peacekeeping force. (A12:1-2.)

Acknowledging that his country had been experiencing a crisis of confidence, Luis Ugueto, Venezuela's Finance Minister, asked international bankers yesterday to convert their short-term loans to Venezuelan Government agencies into longer-term credits to the central Government. Mr. Ugueto, speaking to a group of international bankers at the Plaza Hotel in New York, said that many foreign banks had been declining to renew loans to companies owned by the Venezuelan Government. He warned the bankers that ''being too closed can do irreparable harm.'' Venezuela's problem, Mr. Ugueto contended, is that many banks have been declaring the whole of Latin America ''a problem zone.'' As a result, many regional banks have been reducing their loans to Venezuela, a member of the Organization of Petroleum Exporting Countries.

The construction that began yesterday on the Cathedral of St. John the Divine was full of promise for the future of New York City. It represents not merely the continued growth of one of the city's greatest works of architecture, but also the success of a remarkable work program: the cathedral's decision in 1978 to give young residents of Morningside Heights, Harlem and Newark employment by training them in the ancient art of stonecutting. The cathedral is being built by a crew of roughly two dozen artisans who have been apprenticed under James Bambridge, the master mason who came to Morningside Heights in 1979 from Liverpool, England, to oversee the construction. Nothing would seem, on its face, more outlandish -the notion of giving neighborhood youths employment by training them in an ancient art - but it in fact has turned out to be an absolutely natural marriage between the needs of the cathedral and the needs of the surrounding community. The cathedral had stopped building during World War II, and work was not resumed after the war largely because the Episcopal Diocese of New York felt that the erection of a lavish structure would be symbolically inappropriate until the poverty of its upper Manhattan neighborhood could be alleviated.

The American Can Company, continuing a shift away from the packaging businesses, said yesterday that it had agreed in principle to acquire Penncorp Financial Inc., a general insurance company, for $295.4 million in cash, notes and cash. American Can also said it planned to take a $250 million pretax write-down of some of its holdings and eventually sell them. The after-tax write-down, to be charged against the current quarter's earnings, would be $175 million, or $9.50 a share. The company earned $19.7 million in its 1981 third quarter.

A joint Senate-House conference committee approved landmark legislation today to subsidize the nation's ailing savings institutions and give them broad new lending powers similar to those of commercial banks. The legislation also authorizes commercial banks, along with savings institutions, to market a new type of federally insured account nearly identical to the high-yielding money market funds. These funds have attracted more than $200 billion in recent years. Much of that money might otherwise have been deposited in banks and other financial institutions.

By seeming to say Tuesday night that the United States Marines would not be withdrawn from Beirut until Syrian and Israeli forces had left Lebanon, President Reagan apparently transformed an expectation into a condition. But today Administration officials said there was only one condition for the departure of the Marines - that the Government in Beirut has established its authority. The officials said they ''hope'' this will happen soon. There is no requirement that all foreign forces withdraw from Lebanon before the Marines withdraw, but the Administration's official position is that it expects the foreign forces to depart soon, or as Mr. Reagan said Tuesday night, ''rapidly.''

The operation that started in the Shatila Palestinian refugee camp in Beirut and resulted in the massacre of more than 300 civilians was directed by the top Phalangist military commanders and involved the elite corps of the Phalangist militia, according to Phalangist and Western diplomatic sources in Beirut. President-elect Amin Gemayel, according to the same sources, is not believed to have known much about the operation, which spread to the adjacent Sabra camp. Although he was in the leadership of the Phalangists and now heads the right-wing party, he was effectively excluded from its military circle and was apparently not involved in the planning. His brother, Bashir, who was also President-elect and was assassinated Sept. 14, said before his death that he planned to disband the Christian militia and strengthen the regular Lebanese Army, which is a separate force of about 22,000 men. From the information supplied by the sources, it could not be determined whether the massacre that occurred after the troops went in was planned from the beginning.

NEW rules to regulate more closely the career-counseling industry in New York City are being proposed today by the city's Department of Consumer Affairs. The department's proposals, which have to be approved by the Commissioner of Consumer Affairs after public hearings, follow an undercover investigation by the department into consumers' complaints about the industry and two recent State Supreme Court decisions. In its inquiry, the department found that two companies that charge executive-level job seekers thousands of dollars had engaged in what it described as deceptive and illegal practices, but it took no action against them. The court decisions, which dealt with two other companies, found that they had misrepresented their services, both in advertising and directly to clients, by falsely indicating that they would find jobs for the clients. ''The presentations of some of these firms range from the literally true but deceptive to just plain old lies,'' said Anne L. Carson, the department's consumer advocate. ''These practices are unconscionable because they prey on people who are psychologically vulnerable and want support.''

A landmark bill to aid ailing thrift institutions was approved by Senate-House conferees. The bill, expected to be approved by both houses this week and signed by President Reagan, gives savings institutions a form of Government subsidy and broad new lending powers like those of commercial banks. It also calls for a new account equivalent to money market funds. (Page A1.) A permanent unemployment rate of up to 6 1/2 percent is in prospect, according to Treasury Secretary Donald T. Regan. He said retraining programs are needed to bring the rate lower. (D1.)

''Although it is not possible at this time to predict the precise duration of the presence of U.S. forces in Beirut, our agreement with the Government of Lebanon makes clear that they will be needed only for a limited period to meet the urgent requirements posed by the current situation.'' - President Reagan in a letter to the leaders of Congress. (A12:1.)

The times, they are tough in Kilkenny, Ireland A2 Pro-pipeline move narrowly fails in House A3 Shultz meets allies on Soviet trade A3 British Laborites reinforce disarmament stand A4 Around the World A7 An unsung staff makes the U.N. hum A10 Proposed Polish labor legislation expected to end Solidarity A11 Government/Politics House votes curb on drunken driving in U.S. A16 Balanced-budget supporters gain votes to force House showdown A19 Worldwide survey sees flaws in illegal alien curbs A20 Congress speeds action on series of environmental bills A21 Newark official tells Gibson jury of blank payment requests B2 Senator Moynihan to base cam- paign on his record as a liberal B4 Rep. Fenwick declines invitation for debate at The Times B10 Wallace defied New South poli- tics in winning B14 Republican stake in Virginia election races is large B15 Washington Talk Briefing B12 Analysis: John Herbers on the President's news conference B12 No ''Auld Lang Syne'' for the fis- cal year 1982 B12 General Around the Nation A18 Brink's defendant contends her food was drugged in jail B3 Color suit recalls lines drawn under slavery B16 Education/Welfare More schools offer classes on tak- ing the college extrance exams B3 The Home Section Home Designers' assistants practice what mentors preach C1 Helpful Hardware C2 The chlordane problem in houses on slabs C3 Home Beat C3 Home Improvement C4 Shopping for British antiques by computer C7 Tired old finishes can be sal- vaged C9 Glittering preview of Fall An- tiques Show C10 Finding elegance in old bath fixtures C10 The career-counseling industry is criticized C1 Hers C2 ''Brideshead'' helping to revive Castle Howard C6 Product design: two shows as- sessed C8 Sex bias is found at V.A. hospitals C11 Gardening C12 A helping hand for injured wild- life C13 Arts/Entertainment Public Library bouncing back from fiscal-crisis doldrums C17 Racism links two films at New York festival C18 Disney studio continues effort to woo back teen-agers C19 Hamilton Jordan's ''Crisis'' is re- viewed C20 At last, liner notes come to cas- settes C21 New comedy series, ''Cheers,'' has premiere on NBC-TV C29 N.F.L. strike upsets pattern of television ratings C31 Obituaries Monty Stratton, pitcher who tried comeback after losing leg B18 Sports Pages Long strike could cause N.F.L. to reduce playoff field to 8 B19 Royals rally to beat Angels and avoid elimination, 6-5 B19 Strachan, former pro football player, sentenced to 3 years B19 Players: The image of Jose Stable and his father B19 Mets lose to Cubs B20 Yankeees trounce Indians, 13-6 B20 Dave Anderson on Robin Yount's bandwagon B21 Features/Notes New York Day by Day B2 Going Out Guide C21 Issue and Debate: controlling the Federal Reserve D1 Editorials/Letters/Op-Ed Editorials A30 Economic analysis on the run Westway weasel Bolivia's democracy recouped Wild jails, closed minds Letters A30 William Safire: The Libs are coming! A31 Anthony Lewis: Middle East choices A31 Ernest F. Hollings: Cheating air travelers A31 John G. Kester: An un-Supreme Court A31 .

The Department of Education today withdrew a number of proposed regulations that critics said would severely hamper efforts to provide an adequate education for the nation's four million handicapped children. However, Secretary of Education T.H. Bell, in an occasionally stormy session of a House subcommittee, resisted demands that he drop the entire package of proposed regulations and start all over. As a result, the Select Education Subcommittee of the House Education and Labor Committee unanimously adopted a resolution disapproving of the full set of proposed regulations. With Congress expected to recess later this week, it is impossible for the disapproval resolution to clear both the House and Senate before then. But subcommittee members said their action was something of an ''insurance policy'' to stem possible efforts by the Reagan Administration to push through any new regulations during the Congressional recess.