THE OFFBEAT, the unusual, isn't hard to find in New York. Really, all that's required is a sharp eye or ear. A subway token is sometimes useful too.

I was in a subway train with a friend, a native New Yorker who had just returned to the city after more than a year at an Army base in Germany. "You know the best way to tell you're in New York?" he asked. I voted for the Empire State Building. He shook his head and pointed to a woman sitting across the aisle. She was tearing the keys, one by one, out of a leather case and whistling "Fly Me to the Moon." "It's because everybody you see in this city acts or looks different. But everybody."

Maybe you had to be there. But that's the whole point of a visit to New York. The citizens are the best show, and the easiest to find. You can get one all to yourself in the front seat of a taxi, you're shoved up against them in subways, crowded together in bars and restaurants, and, look, there they are on the street you're walking down, all eight million of them.

Here's another offbeat truth about New York. It's a daytime city, best appreciated by people who are willing to sacrifice a bit of shoe leather.

The bridges, for instance, are available for walking across. The views are spectacular from the Manhattan Bridge and the 100-year-old Brooklyn Bridge. The Queensboro Bridge, known to locals as the 59th Street Bridge, isn't nearly as impressive, but Simon and Garfunkel wrote "Feelin' Groovy (The 59th Street Bridge Song)" about that span. If the '60s were an important time for you, you might want to walk across that particular bridge singing, "I've got no place to go, no promises to keep." Don't let anybody hear you, of course. You wouldn't want to be mistaken for a New Yorker.

A 10-minute walk from the Manhattan-end of the Queensboro Bridge will bring you to the Broadcast Museum (One East 53rd St.). The Museum occupies the first three floors of a townhouse. Next door, open during the warmer months, is Paley Park, a pocket park with a man-made waterfall and a food stand that sells hot dogs and sodas. Or pack a brown-bag lunch and eat it inside the park. When you finish, buy a museum ticket, $3 for adults, $1.50 for children and senior citizens. There are three 90-minute shows each afternoon in the ground-floor theater, and the second-floor videotheque. The last time I visited, the Muppets were available on the ground floor, Sid Caesar upstairs.

There, on black and white videotape, was an old Caesar skit: a takeoff on Edward R. Murrow's interview show of the '50s, "Person to Person." Carl Reiner was Murrow, Caesar an ultracool jazzman named Progress Hornsby.

Reiner/Murrow explains to the viewers that jazz was born in New Orleans before the first world war.

Caesar's jazzman is shocked. "There was a war?" When he asks how it came out, Reiner/Murrow assures him, "We won."

"Solid," says the jazzman.

The tapes are projected on an oversized television screen, and the audience sits on individual chairs or stools, not theater seats. There you are, away from home, watching rare television footage, somehow feeling as if you were in a friendly living room.

One floor above is the cassette library. Museum visitors can select an hour's worth of viewing from the library's 6,000 television programs. I walked through the two screening rooms, watching pieces of "Gunsmoke," Bob and Ray, the Beatles on "The Ed Sullivan Show," the Yankees beating the Red Sox in the 1978 American League playoff game.

This is no time for reality. Across the street and a few steps east of the museum is Hunting World (16 East 53rd St.), a store that specializes in outfitting big-game hunters. Honest. Let the salesperson show you a $1,300 suitcase--waterproof, heatproof, stainproof--that will hold your food, drink and clothing for that week in the brush. The suitcase is surprisingly light, considering it's the size of an average bathtub. But you might pass up the suitcase made of elephant and zebra hide ($4,000), the elephant-hide money belt ($110), and the elephant-hide loafers ($375). It's sort of silly, and at the same time, quite glamorous.

We're walking west now, to the Facsimile Book Shop (16 West 55 St.). This is a store that specializes in things Irish--from 50-cent portrait postcards of James Joyce, Brendan Behan, Sean O'Casey and Samuel Beckett to the complete works of each man. There are books and magazines and records and songbooks and tin whistles to play the tunes.

Two blocks north is the Spectrum Gallery (30 West 57th St.). The Spectrum is the creation of Bill Goff, a fellow who parlayed an interest in art and sports into a gallery whose walls are covered with sports art. Among my favorites are Joseph Golinkin's 1946 water colors of the Santa Anita race track. Bill Forsyth, a New Mexico artist, specializes in outsized oil reproductions of the baseball cards in his collection--Roberto Clemente, Willie Mays, Mickey Mantle are currently on view. Forsyth must keep his collection in his wallet because he paints in the creases as well. The show running March 10 to April 8 is "Lines of Scrimmage," a group football exhibit that includes paintings by three professional players and a needlepoint by Rosey Grier.

A different area of Manhattan to walk through is the plant and flower district, on Sixth Avenue between 26th and 30th streets. (Sixth Avenue is New Yorker talk forthe Avenue of the Americas.) If there's less sidewalk available on this route, it's because of all the plants and flowers.

Walk west at 30th Street until you reach Gleason's Gymnasium (252 West 30th St.). There isn't much of a fight game left in New York, but you wouldn't know that on a good day at Gleason's. Gerry Cooney, the heavyweight who lost his chance at Larry Holmes' title last June, trains there, when he's in the mood. And so are dozens of other suspects and prospects.

There are sparring sessions in the two rings--the busiest time is usually after 3 p.m.--and sometimes stranger sights. My wife and I visited one day when a professional wrestler, one Ivan Putski, was standing in the center of a ring breaking cinder blocks over his head for a television camera. Later, while watching two boxers spar, this same Putski stole up behind us and kissed my wife on the cheek. My face must have indicated a touch of displeasure because Putski broke into an ingratiating smile. "I kees your wife, but not to feel bad," he said. Then he kissed me.

The admission at Gleason's is likely to be a dollar, depending on who's standing near the door, how they're feeling when you walk in, what you're wearing, and whether they think you know a left hook from a right now.

We're going to keep walking downtown. Forbidden Planet (821 Broadway) is a store for comic-book fans. There are thousands of comic books, the oldest and newest, on the main floor and in the basement. The last time I checked in, I was after a copy of Nutsy Squirrel. Nutsy ran around in a long, wide tie, nothing else. His neighbors, birds, were his major headaches. Forbidden Planet didn't have any Nutsy books. On the other hand, they had lots of Pogo.

Across the street is the Strand bookstore (828 Broadway). A good reason to visit the Strand is the extensive selection of new books at half price, usually reviewers' copies. The rest of the store and basement is wall-to-wall and floor-to-ceiling books. There were any number of second-hand book stores in the neighborhood but a good many of them have shut down, victims of high rent and a residential boom. Then again, if you make a careful tour of the Strand you won't have time to visit any other bookstores. The Strand, by the way, is surrounded by stores that deal in antique chandeliers, Art Deco furniture, and, at 799 Broadway, Speakeasy Antiques. Speakeasy is a trip through America of the '30s, '40s, and '50s. Political buttons, rock 'n' roll souvenirs and Hollywoodiana. You can do wonders for your Shirley Temple collection.

One of the best walking streets in Greenwich Village is Bleecker, between Seventh and Sixth avenues. Vanessa, a restaurant, is at the corner of Seventh Avenue, 289 Bleecker. I read in a gossip column that Robert Redford was seen there. Across the street, at 278 Bleecker, is John's Pizzeria. John's menu lists 54 pies, prices ranging from $5.50 to $10 for No. 54, large. Extra cheese is 50 cents, extra essence is a quarter. Essence is garlic. Despite that, John's is so popular, people wait in line, on the sidewalk, to sit at the rickety tables. Bill Murray, the comedian, eats there. I know that because there's a picture of Murray in the window. He has a knife and fork in his hands, a napkin tucked into the top of a Hawaiian sport shirt and a look in his eyes that says No. 54.

Bleecker Street offers a collection of antique clothing, toy and furniture stores, and specialty food shops, not the least of which is A. Zito and Sons Bakery (259 Bleecker). Zito's sells white and whole-wheat loaves in sizes from seven ounces to one pound, 11 ounces. Just west of the bakery is the corner of Bleecker and Cornelia. Murray's Cheese Store is at 42 Cornelia, and his prices are wonderful. Take your bread and cheese and walk to Washington Square Park. Sit on a bench, enjoy your food, and if you like, watch the chess players in the southwest corner of the park.

If chess is your game and you can't get a game, walk out of the park, and one block east to Sullivan Street. Chess Mart (240 Sullivan) offers 15 tables for chess, backgammon, Go, Scrabble, checkers. For 75 cents an hour a player, you could find yourself sitting next to a grand master. Or a beginner. Owner Jerry Yellen sells coffee, tea, soup and doughnuts to keep the players going. Yellen says it isn't unusual for players to arrive when he turns the key, at noon, and leave when he closes, 1 a.m. To keep their minds on chess, he plays Mozart. When the chess business is quiet, and the regulars haven't shown up, Yellen says, "I play rock 'n' roll for myself." Unique chess sets are for sale, including one board whose opponents are the 1972 presidential candidates--Nixon and his men against McGovern's crew.

The last mile: If you find yourself in Chinatown, try to stop by the Chinatown Fair near 8 Mott St.. It's a video-game arcade with a difference. One of the games is an electronic tick-tack-toe board. Your opponent is a live white chicken. The chicken always goes first, and always plays the Os and always wins. And when she does, a sign lights up above the board that reads "Bird Wins." As if you hadn't noticed.

Since you can't believe a chicken is taking you at tick-tack-toe--at anything--you keep playing her. You keep losing. Chinatown Fair promises a large bag of fortune cookies to whomever beats the chicken. That isn't why you keep playing. It has something to do with pride. With not wanting to look like a chump in New York. Besides, you're having fun and you've got no place to go, no promises to keep.