U.N. Ambassador Andrew Young counseled yesterday that U.S. concern (a lot of it voiced from the State Department building where he said) over Cuban troops in Angola was exaggerated.

Americans shouldn't get all paranoid about a few Communists, or even a few thousand Communists," Young said.

This self-proclaimed foreign policy point man of the Carter administration has been shot at from editorial offices, Capitol Hill, Foggy Bottom and various foreign capitals, just about everywhere except the White House.

He called in reporters yesterday seeking an opportunity to explain his motivations and defend his past remarks off the record - in effect, to quiet the fire from one quarter.

"I don't see where any harm's been done," Young said of his controversial statements after agreeing to reporters' requires to speak on the record.

He said the success of his February trip to Africa was based upon his credibility which was enhanced by his public pronouncements.

The White House continues to encourage him to speak out even though he has urged them to let him know if he's having a negative impact. Asked whether the State Department encourages him, he replied: "They don't discourage me."

Again and again, Young said the United States must get away from "knee-jerk reactions" and examine what is really going on in Africa before making policy.

Young compared the U.S. reaction to Cubans in Anola to Washington's concern when Chinese arrived in Tanzania and Zambia to build a new railroad in the 1960s.

When his comparison of roughly 13,000 Cuban troops with Chinese railroad construction teams was challenged, Young argued that manY Cubans are not combat soldiers but technical advisers in various fields.

Every African nation desires genuine nonalignment, Young said. He dismissed fears of Cuban-Soviet gains on that continent.

"We don't have to fear communism in the area of economic competition. The sooner the fighting stops and the trading begins, the quicker we win," he said. At a certain level of development, he said, nations will always turn to the West because of its technological superiority over Communist nations.

The African nations that seek to develop a form of socialism along the Tanzanian model, the ambassador said, are likely to be those that are short on natural resources and in which the West does not make large investments. African socialism should not be seen as a threat by Americans.

Young defended his statement that the Cubans bring a certain stability to Angola which he called the start of "my career? as a center of controversy. He argued that when Gulf Oil operaions are functioning in an area dominated by Cuban troops that is a form of stability. Gulf operates in Cabinda, Angola's northwestern enclave cut off from most of Angola by a piece of Zaire's territory.

Young said the invasion of Zaire's southermost province, Shaba, from Angola was not a clear-cut Moscow Cuban operation.

Zaire conditions to be a good friend of the United States, Young said, but "it is not Washington's duty to defend Zaire's territorial integrity. Zaire said, has received a good share of U.S. aid in the past, implying that it should defend its own territory. The Zairian army has failed to put up any significant resistance to the invaders, all reports.

Young clearly wanted to communicate to the reporters that he does not speak without thinking but talks from a serious concern that African policy be freshly appraised without reference to Cold War concerns.

Many of his sentences were diplomatically gray, hardly words worth a line in reporters notebooks. But reporters scribbled furiously as he answered the final question with his advice on paranota about Communists.

The question came after the session had been declared ended by State Department spokesman Hodding Carter III, and before responding Young said: "I should never answer these extra questions."