Detroit Mayor Coleman Young had barely told members of a national black leaderhip conference today that he was supporting President Carter's reelection before the boos began.

"If you boo, who the hell are you?" angrily snapped Young."I'm going for Jimmy Carter, you can make up your own damn minds."

The boos and Young's outburst were a sharp reflection of the tensions running through the gathering of about 1,000 of the nations's leaders who are supposed to be devising a list of goals important to black Americans during the 1980s.

Leaders of the four-day convention, called the National Conference on a Black Agenda for the '80s, had planned to avoid choosing sides over presidential candidates and instead discuss issues and goals.

Those issues were supposed to be subjected like employment, housing, affirmative job action and voter participation. But national politics has continued to dominate the sessions.

Detroit's Young left the meeting today angry and bitter, saying the conference was a failure.

"I'm not sure what the focus of this conference is, but one thing is certain," he said, "This is not a mass conference but a leadership conference of people with axes to grind. Everyone here is part of some organized lobbying group," said Young.

"These folks are bull -- -- ," Young told a reporter as he left the conference early. "They are not addressing the realities. We have a political election campaign going on."

For his part, Young, who is platform chairman of the Democratic National Convention, said he had no hesitancy to discuss specific candidates. Detroit's revitalization and decreasing crime rate, he announced from the podium, are products of "Jimmy Carter's money."

Carter supporters and those backing Sen. Edward Kennedy (D-Mass.) were hosts of hospitality suites in hotels held late-night strategy meetings, and passed out Kennedy and Carter buttons and literature. Del. Walter Fauntroy, a Kennedy supporter, worked a hospitality suite on the third floor of the John Marshall hotel here while five floors above, Ben Brown, deputy Carter campaign director, did the same.

There were prominent officials from the Carter administration and D.C. Mayor Marion Barry and council member Charlene Drew Jarvis (D-4) both Carter supporters, also appeared.

Barry, who has instituted a freeze on out of town travel by District workers, noted he had paid the way for himself and hiw wife, Effi.

A presidential forum scheduled for Sunday was cancelled late Friday evening when the three cnadidates who initially agreed to appear to discuss the black agenda declined. They were Sen. Kennedy, Rep. John Anderson (R-Ill.) and California Gov. Jerry Brown.

"Some people who have been lobbying said they feel betrayed that the candidates didn't show after they set up the hospitality suites," complained M. Carl Holman, head of the National Urban Coalition.

Reactions to the cancellation ranged from resentment to resignation, but conference organizers attempted at a noon press conference to rekindle enthusiasm.

"We're not going to be defated by the absence of the candidates," the Rev. Jesse Jackson told reporters. "We know the importance of our 10 million votes. We can vote Democratic, Republican or we can go home. Any way we vote we will have an effect on the election."

Jackson, who the day before criticized President Carter for "not discussing the issues" said today that "Kennedy perhaps did not appear because he would have to confront (his part) in the defect of (black former Republican Sen. Edward) Brooke." (At the time of his defeat Brooke, a Massachusetts congressman, was the only black in the Senate.)

"We don't have the problem, the candidates do," said Vernon Jordan, head of the National Urban League. "We have something they need."

Although much attention was focused on presidential politics some delegates said they were finding the confrerence useful.

At one workshop entitled "Voter Mobilization, 1980s and Beyond," more than 400 people discussed ways to increase black participation in local and state elections.

"We need to be informed on the issues, we need to know how to maneuver and manipulate the process that affects us," said a law student from North Carolina State University.

"Elected officials should not be so far from us but should educate us."

Councilman Wendell Ford, of Broome County, N.Y., said, "I have heard every major black speaker talk about the same thing. What we need is the superstars to help us at the local levels and come to the housing projects where our people are and help us get out the vote so that in a county that is abot 55 percent black, more than one black councilman can be elected."

"Everything is more complex," said Lavonia Allison, a delegate from the North Carolina Black Leadership Caucus. She said blacks should seek equal time on the networks because she said the networks do not discuss issues important to blacks.

"To solve the problems of inflation, unemployment, and housing requires tremendous sophistication," Allison said."It is easier when we were dealing with racism at the lunch counters. Now we have to deal with budgets and international problems. To do that, you need to have a broad information base. We've got to transmit that down to the level where the average person can understand.