Life everyone else at Wimbledon yesterday, Pam Shriver, who has stormed into the third round of women's singles, marked time as an all-day rain forced postponement of play in the tennis championships.

Shriver came out to the All England Lawn Tennis and Croquet Club on Monday, the first day of this year's championships, and had a long curious look around the place. She wanted to see if her sport's ultimate shrine matched the vivid impressions she had formed from reading about it and watching it on television.

She roamed around the outside court, through promenades jammed with more spectators than she had imagined. She investigated the elevated, glass-in players' tea room, which affords a panoramic view of the premises, and gazed for a long time at the vine-covered walls that enclose the Center Court.

"That was the first thing that caught my eye as I came through the gates, "said the soon-to-be-16 from Lutherville, Md. "I love Ivy - the way it looks and sounds in the breeze. I'll always remember that first glimpse."

Westminster Abbey, Big Ben and Buckingham Palace would have to wait. Shriver wants to see the sights of London, but not until she is out of the tournament she has dreamed about playing for nearly half her life.

"The first memory I have of Wimbledon was the last year Rod Laver won," she said. That would have been 1969. She celebrated her seventh birthday that week, on July 4.

Now she is at Wimbledon herself, as a competitor, as excited as a young scientist making a first visit to the Royal Academy, or a budding politican checking out the halls of Parliament.

Her leisurely walk around the grounds was part of Shriver's preparation for her first match the following afternoon.

"I don't think anybody can really tell you what it's like until you actually see it and absorb the atmosphere. I thought it would be wise to come out a day early so that I wouldn't get overwhelmed by it right before my match.

"As we drove in, people crowded around the car to see who was inside. They wanted autographs. I couldn't believe that some of them knew who I was. The place has so much character, it's awesome. It's neat."

Her coach, Australian-born Don Candy, a former international player who now teachers in Baltimore, had advised her to get acclimated.

"He told me that it's important to keep your mind clear when you play here. You can get swallowed up pretty easily in the surroundings," she said.

"I wanted to get off to a good start, to make the first step right," added the bright teen-ager, who wants to combine her junior and senior at the McDonogh School in Baltimore so that she can graduate and turn pro in June, a month before her 17th birthday, "Because I hope to be here a few more times."

Undoubtedly she will be. Shriver is 6 feet tall, weighs 145 pounds, and is still growing. She has a fine serve and volley and is improving rapidly under Candy's tutelage. In addition to shot-making talent she seems to have a gift for match play, a court sense and an aggressive instinct that have caught the eyes of knowledgeable observers.

Shriver - a distant cousin of 1972 Democratic Vice Presidential candidate Sargen Shriver ("I've never met him, but he sent me a letter when I started doing well, saying thanks for admitting you're related to me") - is one of two 15-year-olds in the women's singles draw. The other is Californian prodigy Tracy Austin, six months her junior.

Last year Austin - 5 feet tall and weighing 90 pounds - celebrated Wimbeldon's centenary by becoming the youngest player to compete in the oldest and most important of tennis tournaments. She won one round, then lost to Chris Evert, the reigning queen of women's tennis, on the center court.

Austin went on to reach the quarterfinals of the U.S. Open in September and earn the No. 4 U.S. women's ranking. Her success gave hope and encouragement to other teens longing to jump from the deepening junior ranks into the women's major tournament circuit and challenge the power elite.

"The only measuring stick I had when I started playing adult tournaments was that I had played Tracy three times in the recent past and had gone three sets with her each time. Then I saw her beating top players and figured that I couldn't be that far behind," said Shriver, who is winless in six matches against Austin, still marginally behind precocious contemporary.

Shriver doesn't have the giggling, little girl manner that makes Austin seem such an anomaly when she beats up on her tennis elders.

Because she is so tall and so mature in manner, Shriver seems too old to be worrying about Algebra II. But she is appealing, too, in a completely different way from Austin.

Shriver played her first pro tournament, the Virginia Slims of Washington, in January, and won a satellite event - the Avon Futures of Columbus, Ohio - two weeks later, winning 12 matches to go all the way from preliminary qualifying to the championship.

That earned her a berth in the Dallas Slims tournament, where she upset Dianne Fromholtz, Regina Marsikova and Kerry Reid (the No. 8, 15, and 10 seeds at Wimbledon) before losing a tough match to Evonne Goolagong in the semifinals.

Shriver has done all that was expected of her in her Wimbledon debut: won her first two rounds. Anything more will be extra cream on Wimbledon's traditional strawberries.

In her debut Tuesday, she beat Mimi Wikstedt, a chunky 24-year-old Swede, 6-3, 6-3, on court No. 4, in one of the most distracting corners of Wimbledon.

It is a difficult court to play on separated by only a 10-foot-high green canvas backstop and a bed of shrubs and climbing roses from the bustling concourse between the outside courts and the Elizabethan-style structure that houses the center and No. 1 courts.

This concourse is always full of traffic, pedestrian and vehicular, and a bit noisy. It sounds are those of shuffling crowds, regularly punctuated by the shrill voices of vendors peddling ice lollies and other goodies and squealing schoolgirls seeking autographs.

But Shriver turned off all intrusions nicely. She was purposeful and efficient.

"I knew from the beginning that I was going to be okay," she said. "I wasn't talking to myself. You can bet that when I'm talking to myself, I'm not concentrating."

On Wednesday Shriver beat Robin Harris, a 22-year-old Californian, 6-0, 6-0, and probably will play 14th seeded Sue Barker of Britain, a semi-finalist here last year, tomorrow.

"IN the beginning, in January and February, nobody know who I was and there was no pressure at all," Shriver said. "Now, since Dallas, people have talked about Tracy and me and they expect us to win. There's more pressure.

"But I think I like the pressure."