What was going on when I was born?

The Reagan Administration's ambitious plan to remove wellhead price controls on natural gas survived its first major challenge today when the Senate Energy Committee defeated a move to put members on record against decontrolling inexpensive ''old'' gas. Although the sense of the committee resolution offered by Howard M. Metzenbaum, an Ohio Democrat, was not binding, the 10-to-8 vote against it meant that the decontrol of old gas had the support of half the members. There were two abstentions: John Melcher of Montana and Spark M. Matsunaga of Hawaii, both Democrats. ''There is support out there for decontrolling natural gas,'' an Energy Department spokesman commented. ''We think it's a good first step.''

A chart in Business Day Wednesday listing acquisitions of regional brokerage houses by other firms included two errors. The New Court Securities Corporation, which changed its name last year to Rothschild Inc., has not been acquired. Hartford Insurance acquired only a 25 percent interest in Wheat, First Securities Inc.

One of two bodies dug up on Staten Island was identified today as that of a 17-year-old Brick Township girl who disappeared on Halloween night in 1981, and the Monmouth County Prosecutor said he would seek a murder indictment in the case. The Prosecutor, Alexander D. Lehrer, said the girl, Maria Ciallella, had been walking home along Route 88 when she was picked up and killed by gunshots to the head. The killer, he said, was Richard F. Biegenwald, who is suspected of slaying at least four other people in New Jersey. The two bodies were found Tuesday morning in the backyard of Mr. Biegenwald's mother on Staten Island.

NEW YORK being the cultural center it is, many weekends during the season offer a bubbling variety of contemporary-music concerts, but this weekend seems hyperkinetically active. Composers and performers can be found purveying music that reaches from the most refined products of an ''uptown,'' complex sensibility to the meditative or abrasive effusions of the downtowners, from mainstream 20th-century European masters to eccentric Americans, from earnest academics to musicians who used to play jazz but who now work in a style called ''music from the jazz tradition'' - which they rightly espouse as just as legitimate a form of contemporary composition as any other. Highlights include two major British groups here courtesy of the Britain Salutes New York festival, a fascinating program of jazzbased composers working in classical idioms, several important jazz concerts highlighted by two Sonny Rollins shows at Town Hall, an all-20th-century organ-and-orchestra program with Anthony Newman, a microcomputer electronic-music festival at the Public Access Synthesizer Studio and a Frederic Rzewski piano recital at the Third Street Music School Settlement. The most prominent of the English groups is the Fires of London, which will perform three programs tonight, tomorrow and Sunday at Symphony Space. This is Peter Maxwell Davies's group, Mr. Davies being one of the liveliest, boldest and most important British composers of the present day.

Orders to factories for durable goods edged up three-tenths of 1 percent in March, the Commerce Department reported today. Increases for military hardware, machinery and household goods outweighed declines for the transportation industries and primary metals. The new overall gain was the fourth in the past five months and marked a rebound from the revised 3.5 percent decline in February.

The senior commander of El Salvador's guerrilla forces, Salvador Cayetano Carpio, died last week in Managua, according to Salvadoran guerrilla and Nicaraguan Government reports. His death raised questions about the future political and military situation in El Salvador and provoked speculation about rifts among the guerrilla movements of Central America. The Nicaraguan Government and the Popular Liberation Forces, the Salvadoran guerrilla faction that Mr. Cayetano Carpio led, said late Wednesday night that the 63-year-old guerrilla leader had committed suicide. Resisted Negotiated Settlement They said he did so after discovering that a trusted aide had been behind the recent murder of Melida Anaya Montes, another leading member of his guerrilla faction, one of five allied as the Farabundo Marti National Liberation Front. The Nicaraguan Government had earlier blamed the Central Intelligence Agency for her murder.

The United States Government and the State of California filed suit today in Federal District Court here to force operators and major users of the Stringfellow Acid Pits hazardous waste dump to pay as much as $40 million to clean up the site. The site was described as a ''serious threat'' to public health. Named among the defendants were some of the nation's largest industrial concerns, including the General Electric Company, the National Distillers and Chemical Corporation, the Alcan Aluminum Corporation, the Weyerhaeuser Company, the McDonnell Douglas Corporation, the Rockwell International Corporation and the Stauffer Chemical Company. The companies had legally dumped hazardous wastes at the site, 50 miles east of Los Angeles.

PUMP those tires, check those chains, shine those spokes until they sparkle - this is the time of year when bicycling becomes contagious for everyone from competition-class cyclists to those who only wobble and weave. This weekend, the clicking of gears and the squealing of hand brakes will be heard almost everywhere, with a 17,000-cyclist, five-borough bike tour scheduled for the city and several smaller organized journeys planned for nearby bikeways. But for cyclists who are less accomplished, or who don't want to be in the thick of the Five Boro Bike Tour's pedaling throng, there are plenty of out-of-the-way places where one can ride at a leisurely pace, stop for a picnic, listen to the waves on the beach or perhaps catch a glimpse of a bald eagle. And, of course, there is always Central Park. The region's bikeways are fairly evenly distributed among four of the five boroughs and the surrounding suburban communities. In New York City, there are 111.3 miles of bikeways (72.4 miles more are planned). The city's path-builders have more or less overlooked Staten Island, but its traffic patterns tend to be less frantic than those in the other boroughs.

Derek C. Bok, the president of Harvard University, assailed the American legal system yesterday, calling it ''among the most expensive and least efficient in the world.'' He said law schools bear part of the blame. In his annual report to the Board of Overseers of Harvard College, made public yesterday, the 53-year-old lawyer and former dean of the Harvard Law School says the legal system is too costly and complicated and places the interests of the privileged ahead of justice for poor and middle-class citizens. He also said law schools attracted too high a percentage of the most able college graduates. He called this situation ''a massive diversion of exceptional talent into pursuits that often add little to the growth of the economy, the pursuit of culture or the enhancement of the human spirit.''

The Economy The Senate voted to delay tax withholding on income from interest and dividends for at least four years. The compromise plan, which includes measures to increase tax compliance, faces an unsure future in the House and at the White House, however. President Reagan, a strong withholding advocate, is described by aides as unlikely to change his stand. (Page A1.) Disregarding a White House plea for delay, a bipartisan alliance was formed on the Senate Budget Committee to break an impasse on the 1984 budget. (B6.) Orders for durable goods edged up 0.3 percent in March, the Commerce Department reported. The gain, the fourth in the last five months, marked a rebound from a revised February decline of 3.5 percent. Officials said increases for household goods and business equipment suggest further production gains are under way. (D1.)

The Puck Building in SoHo, a Romanesque Revival landmark named after the satiric weekly that was published there, is celebrating its recent restoraFrom Puck 1876-1918: Puck Magazine's Profile of an Era.'' More than 200 lithographs and original drawings from the defunct publication will be on display through Aug. 28 - caricatures of Mark Twain and Thomas Edison, for instance, and cartoon assaults on Tammany Hall politicians, candidates for President, monopolists and overcrowded public transportation. The show is on the second floor of 295 Lafayette Street, at the corner of East Houston Street, and is open from noon to 5 P.M. Thursdays through Sundays. There is no admission charge. JUILLIARD THEATER OPENS The Juilliard Theater Center has been the training ground for such actors as Kevin Kline, Patti LuPone, Elizabeth McGovern and Christopher Reeve. Tonight at 8 the current company opens its spring repertory season with Congreve's ''Love for Love,'' described by the director, John Blatchley, as ''a gentle play, a Restoration equivalent of boy meets girl.'' Opening tomorrow at 8: a rare production of Robert E. Sherwood's ''Petrified Forest,'' the subject of a 1936 film with Leslie Howard, Bette Davis and Humphrey Bogart, in which gangsters take over a roadside restaurant in Arizona. Tickets: $7. Information: 799-5000.

''The law may seem enlightened and humane, but its constant stream of rules will leave a wake strewn with the disappointed hopes of those who find the legal system too complicated to understand, too quixotic to command respect and too expensive to be of much practical use.'' - Derek C. Bok, president of Harvard University. (A1:6.)