Martina Navratilova would like everyone to know that she is happy.

Not necessarily with her tennis, although that may be coming around, too. Her form in beating Wendy Turnbull yesterday on the opening day of the $250,000 Colgate Series Championships at Capital Centre suggested so. But she would like the world to know that she is happy, with herself and her life.

"It was getting on my nerves, all these stories saying that Martina is depressed, distressed, troubled, she's really having bad times," said the 24-year-old expatriate Czech, recalling the spate of reports that attributed her slide from No. 1 to No. 3 in the world rankings last year to nebulous "personal problems."

"Off the court, I'm the happiest I've been for a long time. My personal life is nobody's business, but if people do write about it they should know, or at least ask me so that I can tell them myself."

Navratilova is the first to admit that 1980 had its difficult moments for her, professionally and emotionally.

She was upset that her family, which finally got an exit visa from Czechoslovakia and joined her in the United States just before Christmas, 1979, had trouble adjusting to America and accepting her independent life style. Their reunion, bringing them together for the first time since she defected in 1975, was joyous, but it became increasingly strained. In August, her father, mother and teen-age sister returned to Czechoslovakia.

Navratilova also resented persistent and tactless prying by the press, particularly in England, into her friendship with noted feminist Rita Mae Brown, the gay activist author and lecturer with whom she shares a house in Charlottesville.

It was to get away from the pace and pressures of celebrity that Navratilova bought her 20-room English stone house on nine acres of picturesque land atop a hill on the outskirts of tranquil Charlottesville.

"It reminds me of Czechoslovakia in a way. Not that I want to go back there, but the countryside is very pretty. I think you always try to go back to your roots in any way you can," said Navratilova, who loves America (she is awaiting citizenship, and hopes the paperwork can be completed by April) but still has fond attachments to her homeland.

"I just feel relaxed, at ease with myself in Charlottesville. It's getting away from the big cities. The whole year we're in big cities, hustle and bustle, and there you can get close to the country and not have to worry about people looking down at your window."

People have been trying to look at her window, however, and it understandably bothers her.

"Nobody's private life should be under that public scrutiny," she said. "People ask, 'What about your private life?' And I say, 'If it's supposed to be private, don't ask me about it.'

"I was reading all these inaccurate things, and it was eating at me. The main thing that was eating at me was my family. That was the hardest one. But then I was getting hassled, especially in England, being followed by reporters and photographers wherever I went."

The most sensational of the British tabloids can be relentless and tasteless in their hounding of celebrities, and their attention to the friendship between Navratilova and Brown finally prompted Navratilova to an angry outburst at a Wimbledon press conference. "In Czechoslovakia, there is no freedom of the press," she said bitterly, "and in England there is no freedom from the press."

Navratilova refused to use any of this as an excuse for her semifinal loss to Chris Evert Lloyd at Wimbledon, where she had reigned in 1978-79, but undoubtedly the intrusions and distractions didn't help her tennis.

"Once I'm on the court, I don't think about it, but the hassles make your life more difficult," she said. "What bothered me was the total intolerance, the insensitivity of some of these people. There is no such thing as privacy in England. I was mostly mad that human beings could treat others like this. I know reporters; I know it's their business, but, Jesus, they could have a little heart. I think I was more disappointed at people than anything else."

At the same time, there was the problem with her parents. Navratilova had looked forward so long to being reunited with her family that she never really imagined it might not work out. She had taken to America so quickly when she first came here to play tournaments at 16, had picked up the customs and the language so easily, that she didn't foresee their problems of adjustment.

"It was wonderful at the beginning, but then it got to be very, very difficult," she said. "I tried to make them comfortable, but it didn't work. My father is not very good with languages, and that was the biggest problem; he just couldn't communicate with anybody."

"Then I had the same kind of situation people do when they come back home after being away from college and their parents try to tell them how to live their life. I had been on my own for five years, and then here come my mother and father telling me exactly what to do with everything: what time to go to sleep, what time to get up, what to wear.

"Maybe everyone goes through that with their parents. It was hard for them to accept that I was a grown-up woman, on my own, able to take care of myself. But mine was a double-edged sword, because at the same time they were trying to adjust to living in a strange country. Finally, they decided to go back home in August, so my sister could start the school year in Czechoslovakia."

The off-court distractions undoubtedly affected Navratilova's explosive tennis, which is based on precise timing and leaves little margin for error. After winning her first 28 matches and five tournaments of 1980, including the Colgate final, she didn't win another major title.

Still, she had a bad year only by the loftiest standards, winning 11 tournaments and a women's record $797,487 in prize money. In Tokyo in the fall she showed signs of returning to form, beating Tracy Austin and Evert back-to-back in straight sets. Yesterday she trounced Turnbull, who had defeated her in their last two meetings, 6-2, 6-4, and felt her touch and timing coming back.

"I always get excited at the start of a new year," she said. "We're playing indoors again, on carpet, and those are my favorite conditions. I think I've been kind of written off, but my game is still there. . . I hit some shots I haven't hit in a long time."

Lean and hungry at 140 pounds after four weeks of purposeful practice and lifting weights, Navratilova grinned when informed that Evert had wondered aloud if she is "desperate to be No. 1 anymore."

"She'll find out. I don't think you have to be desperate to achieve something, but I still want it. I just want it in a different way," said Navratilova, who has expanded her intellectual horizons and interests.

"Three years ago, being No. 1 in tennis was the only thing in my life, and then I got there and found out that's not what it's all about. Playing good tennis made me happy, but winning didn't. Winning Wimbledon was a big high, but it didn't last as long as I thought it should. I needed other things in my life to make me happy, but I still want to be the best."

The recent death of a close friend from a brain tumor at age 36 also affected Navratilova deeply, making her realize how transitory life is. She has dedicated 1981 to the friend's memory.

"I know it sounds corny, but I'm trying to remember her spirit, as a reminder of what's really important," she said. "When I got the news, I just started crying and wondering how this person could die so young. I thought I had to try to do something positive. She would have wanted me to play well, but she'll also be my reminder of how important friendship is. I've realized that it takes more than winning tennis matches to be happy."