Jack Kent Cooke came into his own party last night clearly intending to enjoy the moment. His Redskins are the National Football Conference championship winners, and whatever happens tomorrow they can't take that away.

His quarterback, Joe Theismann, looked up from the minicam that has been stuck permanently in his face all week to say, "Oh no--don't steal my thunder." Cooke only stole about two minutes worth of TV time, leaving Joe to say, "How do I follow that?"

Cooke was on a roll, he slapped backs, he shouted the names of pals, he introduced his friend and neighbor from Upperville, Va., the Swedish countess Agneta Bonde. It seemed a good night to own 87 percent of Washington's pro football team.

It was also a good night for 9-year-old Michael Terrel of Washington, who was among his heroes at the swank Redskins hotel here. Last year, while the Redskins cheered, Michael put down his crutches and walked all the way up and down the practice field near Dulles Airport.

Also enjoying themselves were Duke Zeibert, the restaurateur, Miss Super Bowl, who mingled beamingly, and the hangers-on, barbecue cookers, passers-by, and geegaw hawkers in this mini-mob scene, played to the tune of "Hail to the Redskins." Into Jack Kent Cooke's celebration party came Coach Joe Gibbs, also enjoying himself. A man must do what a man must do. Relaxation is the key to victory.

Are the players also allowed to have a cocktail? Gibbs was asked. The other 200 enjoyers-of-the-moment were certainly having one.

Gibbs' eyes widened through his aviator glasses.

"Preferably not," he said.

The players on both teams have been ordered by their coaches to "enjoy the moment." By no means are they to dwell on tomorrow's game--which, of course, will have to be the best game they have ever played.

Coach Gibbs of the Redskins: "I told the players we worked hard to get here, having the attention and everything, and we should enjoy it. We'll just steal a little time in the evenings to go over our game plan."

Coach Don Shula of the Dolphins: "I've learned a lot over the years. This team had its first taste of national media exposure last week, and they handled it well. I encouraged them to be around, to be available, to live it."

In other years, Super Bowl teams have tensed up under the strain and "lost because they were afraid to lose." George Allen in 1972 instituted curfews and strict security; but this time there are no curfews for either side.

The veteran players are theoretically the loosest, by virtue of their experience in the limelight. John Riggins dresses like a duck hunter and gives the impression of a fellow happy to have a beer at breakfast. Bob Kuechenberg, the Miami guard who already wears a Super Bowl ring, is very loose after 13 years in the NFL.

Some parts of Kuechenberg, in fact, are looser than other parts of Kuechenberg. Along the way he says he has broken both big toes, one foot, both ankles (one in five places and the other in seven), his right knee cartilage, his back, his shoulder, his left forearm, three of his fingers, his neck, and his nose (four times). He also has what the doctors call a nonsymptomatic ruptured disc. What that apparently means is when the doctor asks him if his ruptured disc hurts, he says no. Nevertheless, the tension builds. Joe Theismann says calmly that "this is just another football game," but then cannot help adding, as his voice rises and his eyeballs bug out, "It just happens to be the most important football game of my life."

What the coaches are giving their teams is a remedial course in foxhole Zen Buddhism, although, of course, they will not admit it. The idea of Zen is that the true goal can be gained only by not seeking it. Flow with the tide, enjoy the moment and naturalness will prevail. The danger, of course, is that A.J. Duhe, the Miami linebacker, will not be able to understand Zen Buddhism, and will merely do tomorrow what he did to the Jets last week.

For heaven's sake fellows, relax. It's just another game. Enjoy the moment.

Hey, aren't the coaches relaxed? Sure, just like the cartoon nanny, who, leaning over the crib with an enormous mallet, says to the wide-eyed baby, "Sleep!" Punk Rock

Los Angeles has a good feeling for spectacle, so the Super Bowl fits right in. For one thing, the weather all week has alternated between sunny 65-degree tropical paradise and howling gales that seem orchestrated by Cecil B. De Mille.

At the King's Marina in Redondo Beach, while gigantic seas sweep the breakwater and wash away restaurants, a policeman on duty worries that the storm will not be over by Sunday. He has tickets to the Rose Bowl and is rooting for the Redskins.

At the Polo Lounge of the Beverly Hills Hotel, NFL staff cars can be seen discharging football relatives into the champagne-soaked night. The accents of Florida mingle with the accents of Hollywood, and talk of option plays mingles with talk of movie options. But, alas, the Polo Lounge is much too crowded to lounge in and where are the ponies?

Across from the Chinese Theater in Hollywood there is a new club called the Seven Seas. It is a haven for punk and New Wave music, and to enter one passes through an offensive line of young men in voluntary baldness and combat boots, accompanied by young women whose hair appears to have been coiffed by a Black & Decker weed eater.

One of them, known as Baby Crazy, has a Mohawk haircut. He does not know who John Riggins is despite Riggins' one-time Mohawk, but then he probably does not know his seven times table either.

"This Riggins," says Baby Crazy, "can he slam?"

Well, Baby Crazy, would you like to find out?

The consensus from Amber, Bobby Bondage, Billy Blaze and Hollywood Julie is that professional football is "bull----," and so is New Wave. So is everything, in fact. They are punks and devotees of a local band called Black Flag, the motto of which is "Black Flag kills ants on contact," an unkindly reference to the New Wave music of a band called Adam and the Ants.

"This Riggins, do he thrash?" asks Baby Crazy.

Oh, if there were only time, sir.

Inside the Seven Seas it is relatively peaceful except for the music, which sounds like a jetliner making a crash landing into a junkyard. Peace is pretty much the work of Greg Kervian, the doorman, who is 6 feet 11 inches tall and, having just lost 70 pounds, weighs a svelte 330. He has never played football, but will watch the Super Bowl on television tomorrow.

"We had nine of the Redskins in here the other night," Kervian alleged. "I didn't get their names, but I saw their I.D. cards and we let them in for free. They seemed to have a good time. There were 1,300 people here and they fit right in."

Well, coach, you said to enjoy the moment. Grass

One of the most startling facts about the Super Bowl field is that all those decorations on the grass--the painting of helmet, the NFL shield, the white gridiron lines--are done with regular house paint. It is absolutely remarkable that painting live grass with house paint doesn't kill the grass.

"The answer to that is that it kills the grass," said George P. Toma, the Michelangelo of turf. "You know that big rose on the field for the Rose Bowl game, January First? Well it killed 60 square yards of grass, which we just replaced."

Toma is the chief of the grounds crew for the Kansas City Royals and Chiefs and was flown in by the NFL to prepare this field for tomorrow. He is the Vince Lombardi of grass seed. He wants each grass seed to give 110 percent and he knows that when the growing gets tough, the tough get growing.

The grass that comes to George Toma is must be a top-seeded crop of Derby, Regal and Elka perennial rye. Only then it is is it welcome to the NFL. "What we do with these new seeds that come in here is called pregermination," he said, striding purposefully across the field. "You want fat growth, you want the job to get done. Fill a 55-gallon barrel with seeds and then fill the barrel with water. Eight to twelve hours later, drain the water out. Put in some new water and then drain it out again. Do that for four to six days. Then dump the seeds on a concrete floor, let them dry and mix in a product, ha ha, which we get from the Milwaukee Sewer Commission. Then aerate the field, pin-spike it, drill-plant it and top-dress it with spent rice hulls."

This is called forcing the seeds. After a training camp like that, the little rye seeds grow so fast they need to be mowed after seven days.

The Rose Bowl grass is superb. Every blade carries George Toma on its shoulders like a triumphant coach. Every seed has realized its full potential. Every seed has earned the right to be there. And every seed should enjoy the moment. Forest Lawn

Not far from the Rose Bowl and Pasadena, across the hills of Glendale, lies another kind of spectacle: Forest Lawn. In its stupendous tranquility, the great Los Angeles mortuary offers a rare chance to reflect on the mutability of all things.

How many have striven for glory in this, the City of Angels! And yet in the end, no matter how fleet the running back, how spring-armed the passer, how loyal the fan, there is always the spectral presence of defeat.

But the builder of this remarkable place knew what he had in mind. It is engraved in stone: "A place where lovers new and old shall love to stroll and watch the sunset's glow, planning for the future or reminiscing about the past, a place where artists sketch, where school teachers bring happy children to see the things they read of in books--where the memorialization of loved ones in sculptured marble and pictorial glass shall be encouraged, but controlled by acknowledged artists--a place that shall be protected by an immense Endowment Care Fund, the principle of which can never be expended--this is the builder's creed."

Let us cruise thoughtfully through the curves of this memorial, past the Wee Kirk o' the Heather, past the temple of Santa Sabina, past the Mystery of Life, past Slumberland, past Babyland, past Lullabyland to end our journey at the Court of David, where a surprise awaits.

Here, 20 feet high, stands a muscular figure in white marble, his noble head festooned with curls. In the quiet grove, movie background music wafts from stereo speakers hidden in the bushes. Two golden-haired ladies who cruise by in their highly polished 1949 Hudson see only the reproduction of Michelangelo's David.

But the statue is, in fact, a dead ringer for John Riggins. Big John, diesel-powered John, Riggo, up on a pedestal in Glendale.

It may be too early even in the case of John Riggins (who has rushed for more 100-yard-plus playoff games than anyone else) to speak of immortality. But all he has to do to be put on a pedestal in Washington tomorrow is bury the fish people from Miami.

Tomorrow is tomorrow. Right now the coach says, enjoy the moment.