The first thing Yannick Noah said he was going to do after winning the French Open was take some time off.

Perhaps he suspected that three days later he would be suspended for up to three months and fined $20,000 for having forfeited a match without authorization during the Nations Cup competition in May 1982. Even before the suspension, Noah had announced that he was not comfortable enough on grass to play at Wimbledon this year.

But perhaps Noah decided to take a holiday because, more than anything else, he enjoys a good party. In a sport dominated either by ranting brats and colorless, machine-like base liners, Noah is an emotional and fun-loving 23-year-old, both on and off the court. Too fun-loving, perhaps, because until the past weekend at Roland Garros, when he became the first Frenchman in 37 years to win the French Open, he seemed to lack mental toughness.

His Rastafarian-style mop flying about, he soars about the court. After winning a point, he often roars and opens his arms wide towards the sky in joy.

At home, Noah is also an extrovert. He delights in fast motorbikes and loud music. He speaks fondly of his copains, who make up some of the brightest members of Paris' jet set.

This fast life is a long way from the streets of Yaounde, Cameroon, where Noah was raised. His father married a white Frenchwoman during his stint as a First Division soccer player in France, and his son was born in Sedan, in the east of the country. But soon afterward, Zacharie Noah injured his leg and, his career finished, he returned to Africa with his son.

A storybook fable followed. The elder Noah fashioned a homemade wood racket for his son. Using this primitive instrument, Noah was discovered by Arthur Ashe during a good will tour of Africa in 1971. Ashe contacted the French Federation of Tennis, which agreed to sponsor the 11-year-old at its tennis school in Nice.

Before too long, Noah showed that he had world-class talent. He grew into a big, powerful young man with the speed of a sprinter. From the age of 15, he traveled with French teams, and in 1977 reached the final of the Orange Bowl tournament in Miami. Not long afterward, he joined the pro tour.

He won a few smaller tournaments during his first year on the tour, awing crowds with his big serve and volley. By 1981, he had moved into the world's top 20 and, by the end of last year, into the top 10.

But if the athletic distance between Youande and Roland Garros, Wimbledon and Flushing Meadow was easily spanned, the emotional distance was not. It soon became apparent that Noah had a concentration problem on the court. He played nervously in big matches, lacking confidence and the finishing instinct of a champion.

Mostly, this was because he has so many interests outside of tennis. What other top-ranked tennis player has taken three months' respite from the tour to study philosophy at the Sorbonne?

Noah has spent even more time off the court having fun. He has had his fair share of adventures, and in his open way, shared them with all of France. In one interview two years ago, he talked about sex in a casual way and shocked many Frenchmen by admitting that he had used marijuana.

He tended to carry this nonchalance onto the court. Winning did not seem very important to Noah. After losing to Ivan Lendl in the quarterfinals at Roland Garros last year, for example, he told stunned reporters that it didn't make much difference, because by getting that far in the tournament he had fulfilled his contract to le Coq Sportif.

Few expected this year to be any different--including Noah. "My coach told me I could win at Roland Garros this year," Noah recounted after his victory, "but I didn't believe him for a minute."

Only against Lendl in the quarterfinals did Noah begin to believe in himself. After winning the first two sets, Noah was ahead, 5-2, in the third set, but he let Lendl fight off three match points and win the next game. Noah's game proceeded to fall apart. He lost the next five games and the set and prepared himself for the seemingly inevitable collapse.

"I nearly died at that point, I was so nervous," Noah said. "I saw myself losing another match after having match point, in the dressing room, all depressed."

But he attacked, and jumped ahead of Lendl in the fourth set. "I regained my confidence," he said, "after playing that good first game." Soon, before a shocked hometown crowd, he had swept the set and match, 6-0.

But the victory over Lendl was not enough to dispel all doubts about Noah's emotional state. In the final, he was a decided underdog against the 18-year-old Swede and defending champion, Mats Wilander, but won in straight sets.

It is far too early, though, to judge whether Noah has the determination, stamina and competitive spirit of a McEnroe, Connors or Borg. He reminded the tennis world of his old foibles by his announcement that he would not play at Wimbledon. He argued that it would take more time than he can spare to adjust his game to grass.

"In five years there, I have won only two matches," he explained. "I just don't think I can get ready for the tournament."

The suspension also recalled Noah's immature side. After France had been eliminated from contention in the Nations' Cup, Noah complained of stomach pains and returned to Paris without informing tournament organizers. He forfeited a scheduled match against West German Damir Keretic.

Noah has announced that he will not play in a Davis Cup series against Paraguay scheduled for July 9-11. Despite this, few here seem ready to criticize him. French champions are a rare breed and, for now, at least, France continues to be enthralled by Noah. Articles about his suspension have been mere two- to three-paragraph blips in the daily papers.

So until late summer, when he begins preparing for the U.S. Open at Flushing Meadow, Noah will get the holiday he wants. He said he plans to use it to celebrate his victory at Roland Garros.

"I'm going to see my friends, of course," he said after the final. And sure enough, photographers spotted him later in the week, rocking and rolling in a fashionable Paris disco. That's the Noah style.