George Bush says he isn't going to be Ronald Reagan's "hatchet man." But two weeks after he was picked as Reagan's vice presidential running mate it still isn't clear exactly what he will be.

Bush, Reagan's second choice for the job, is getting all sorts of advice on the matter.

Sen. Barry Goldwater of Arizona, the Republican Party's elder statesman, has told him, "Do your own thing." James A. Baker Iii, Bush's old presidential campaign manager, has told him not to be a Reagan "clone."

But Bush, in Washington for meetings with congressional leaders yesterday, is still struggling for a new identity.

He hasn't bothered to ask Reagan what he would do as vice president. "If I earn the full confidence of Gov. Reagan, I'll have plenty to do," he told a news conference yesterday. "If he has a lack of confidence in me, I won't have much to do."

He has decided he doesn't have to agree with everything Reagan says -- or back down on his own well-publicized stands on a host of issues.

"I am what I am," he said yesterday. "I'm on the ticket because he thought, and the convention thought, I could help in some areas."

But Bush, who has never been close to Reagan, is still looking over his shoulder, waiting for a favorable pat on the back from his new boss. He is not ready to make any waves.

"I'm not going to go around emphasizing my differences with Ronald Reagan," he said.

At the news conference, the former congressman, "CIA director and ambassador pointedly refused to get involved in the Billy Carter affair.

"The idea on Billy Carter, at least the advice I got from the senators, is very much in accord with the position I'd taken: let the system work. Don't make any allegations," Bush said.

About the only thing he seemed sure of was that he won't be a hatchet man in the campaign. "I've never been any good at trying to destroy somebody's character or tear him down," the Republican vice presidential nominee said. "I've been accused of not being a good gut fighter . . . I don't think there's going to be a special role assigned to me to go about and be some hatchet man. If I was, I wouldn't be very good at it."

Bush paid what amounted to courtesy calls on various Republican leaders on Capitol Hill during his two-day visit, his first trip to Washington since the Republican convention in Detroit. His reception was warm, with conservatives and moderates alike praising the nominee.

Sen. John Heinz (Pa.), chairman of the Senate Republican Campaign Committee, called Bush "our 101st senator" and said his addition to the ticket would help GOP Senate candidates in the Northeast and Midwest.

Bush returned to his family's summer home in Kennebunkport, Maine last night. He will apparently remain there much of August. He, like Reagan, will maintain a relatively low profile for the month, making only occasional campaign swings, aides said.

Meanwhile, senior advisers were negotiating with the Reagan camp on how many people Bush will have on his staff. The number will be about 25.