BAL HARBOUR, FLA., FEB. 17 -- Ann Dore McLaughlin had her formal coming-out with organized labor today and, by most measures, it appeared to be a success.

For the first time since becoming labor secretary late last year, McLaughlin appeared before the AFL-CIO Executive Council, a ritual performed here by almost all of her predecessors in the Cabinet post for three decades.

Substantively, the closed meeting apparently produced what most people here expected: very little. But McLaughlin seemed to overcome much of the initial skepticism among the union leadership about her lack of labor experience.

The meeting was described as "very cordial and very friendly" by several persons who attended. During her time there, an aide said she received 10 or more specific queries on subjects ranging from child care and the minimum wage to labor-law revision and Labor Department enforcement programs.

After the meeting, AFL-CIO President Lane Kirkland gave McLaughlin high marks. "She gave every indication of being on top of her job," he said. "She was well received."

Although Kirkland noted that the unions have basic differences with the Reagan administration on many issues, he said, "I am quite satisfied we'll have a good working relationship with Secretary McLaughlin." He went out of his way to emphasize the positive aspects of labor's relationship with her.

McLaughlin, who had been meeting with various union groups since her arrival Tuesday morning, said the meeting with the council gave her a chance to discuss "a lot of mutual concerns" with the unions.

She said, for example, that she promised to seek their advice on labor matters while acknowledging many policy differences between unions and the administration.

She outlined several areas where she pledged to work with the unions, such as the unemployment insurance system and the often contradictory enforcement policies of her department. In both cases, she said she had set up internal task forces on the problems and had invited AFL-CIO participation.

A McLaughlin aide said the secretary found the meetings useful. "Over a period of two days, you start to hear the common threads of labor's concerns," he said.

Sources close to McLaughlin said she had been nervous about the meetings before she arrived because she was not quite sure what kind of reception she would receive from the union leadership.