President-elect Ronald Reagan today named who managed his victorious campaign to head the transition team for his administration, a job he described as "translating campaign promises into reality."

Reagan also made room among his foreign policy advisers for three prominent Democrats, who join a roster that includes veterans of the Nixon and Ford administrations.

And he gave his strong endorsement to Sen. Howard H. Baker Jr. (R-Tenn.) as the majority leader in the upcoming Republican-controlled Senate. He also said he was taking back into the fold his campaign's final days when questions arose over whether he had used past government positions for private gain.

William Casey, the campaign chairman, will return to his private law practice, but will also head the transition executive committee and the interim foreign policy advisory board, Reagan told his first news conference since his landslide victory over President Carter.

Anne Armstrong, cochairman of the campaign, was named vice chairman of the transition committee.

Edwin Meese, a longtime friend of Reagan who was the campaign chief of staff, will be the director of the Reagan transition team, with campaign veterans Michael Deaver, James Baker, Richard Wirthlin, William Timmons, Verne Orr and Drew Lewis serving as deputy directors, Reagan said.

The president of a Los Angeles executive search firm E. Pendleton James, was named director of personnel management for the transition.

Reagan expressed gratitude that Democrats Sen. Henry M. Jackson (Wash.), Sen. Richard Stone, who just lost his Florida seat, and Washington lawyer Edward Bennett Williams, who led an effort to deny Carter the Democratic nomination, had agreed to join the Reagan foreign policy board.

Its other members, including former president Gerald R. Ford; former secretary of state Henry A. Kissinger; Richard M. Nixon's former chief of staff, Alexander M. Haig; Texas Gov. Bill Clements, Caspar Weinberger; Allen, Armstrong and Sen. John G. Tower of Texas were announced earlier. aReagan fine-tuned two campaign promises yesterday.

He said many times during the campaign that he would abolish the departments of energy and education if elected. He was asked yesterday whether he would, therefore, name Cabinet officials to head those bodies.

"Well, yes, these departments exist, and of course you're going to have heads of the departments. Let me make it also plain that I am aware that in both of these new Cabinet-level departments,there are functions, legitimate functions. . . ."

He said he would not throw out legitimate functions which "have always been performed by government and which should continue to be but have since just been incorporated in those departments."

Reagan declined to discuss specific potential Cabinet nominees, but said "it could very well be" that a Democrat will be given a Cabinet position. He also declined to discuss whether Kissinger would be appointed secretary of state.

Although Reagan pledged to support the GOP platform on which he ran and said he would not turn his back on conservative like to the Moral Majority that supported him, he moved to head off speculation that the conservatives in his party night try to block Baker, the moderate Senate minority leader, from becoming majority leader.

"I not only have confidence in Howard Baker, but I have been informed by members of the Senate that there is no friction, and there is no move going forward to change in any way -- that position is solid. He will be the majority leader of the Senate," Reagan said of the Congress that will convene in January. Baker made a bid for the Republican presidential nomination that aborted soon after its launch.

Reagan also put his personal stamp on the return to his staff of Allen, a White House adviser during the Nixon administration.

Reagan added: "We found no conflict of interest. We found nothing that should change our mind about him. . . ." Allen reappeared at Reagan's headquarters Wednesday. He has been rumored to be a candidate for the post of national security affairs adviser in the White House.

Reagan also stressed his loyalty to the people and policies that won his victory. He said he still feels wedded to the Republican platform although dependents voted for him.

"I ran on the platform, the people voted for me on the platform. I do believe in that platform, and I think it would be very cynical and callous of me now to suggest that I'm going to turn away from it. Evidently those people who voted for me of the [Democratic] party or of the independents must have believed in the platform also," he said.

Reagan also said he would not turn away from organizations like the Moral Majority. "I'm not going to separate myself from the people who elected us," Reagan said of his intention to take advice from the conservative organizations.

Reagan said the exact role for Vice President-elect George Bush will be worked out during the transition, but he described his relationship with Bush as "not only one of a team, but one of a growing friendship." Reagan said, with Bush smiling beside him, "I want to make use of what I think is a very valubale asset."

One theme running through the first Reagan performance as president-elect was his desire not to preempt the powers that belong to Carter until January. wAgain and again, in answer to questions about foreign policy and the American hostages in Iran, Reagan reminded his audience that he is not yet in power. There is, Reagan said, "a delicate point" beyond which he does not intend to go.

Two days into his president-elect status, Reagan also faced a question about the future. The oldest man ever to be elected president was asked whether he had ruled out seeking a second term.

Reagan, 69, took the question with good humor. "No, I haven't thought beyond the term to which I have been elected. And, uh, any question, I feel just fine," he replied.