The fevered action of NCAA basketball may be over, but the collegiate stars of tomorrow are raring to go this Saturday at The 13th Annual McDonald's Capital Classic High School All-Star Game. The game pits a team of this area's best (with an assist from 6'9" J.R. Reid of Virginia Beach) against a squad of some of the most sought-after high school seniors in the nation. Past participants have included Magic Johnson, Ralph Sampson and Patrick Ewing. The game is at 8 (there's a preliminary game at 6 between the D.C All-Stars and Suburban All-Stars) in Cole Field House, University of Maryland at College Park. Tickets are $8 and $10. They're available at TicketCenters or by calling 432-0200. Cherry Blossom Times

The week-long National Cherry Blossom Festival kicks off unofficially Sunday with the Nike Cherry Blossom 10 Mile, one of the top road races in the country. Though it's too late to register for the 10-miler, you can still join in a 3,000-meter fun run, which begins shortly after 8 a.m. in West Potomac Park near the Lincoln Memorial. The first thousand finishers will receive a patch in this free race.. And you won't even have to worry about being trampled by the herd of 5,000 serious racers representing a dozen different countries, because they'll be taking off just before you. 445-4177.

By the way, there'll be a variety of other festival-related events throughout the week, including a Japanese lantern lighting ceremony near the Jefferson Memorial Sunday from 4 to 6; concerts in various parks around town from Monday through Friday; an exhibition tennis match on Monday between Boris Becker and Guillermo Vilas at George Washington University; and a free big-band tea dance Wednesday from 8 to 10 at the Sylvan Theater near the Washington Monument. The parade is Saturday April 12. For schedule and details, call 789-7070. Crash Course

If you're the type who goes to the auto races hoping for a wreck, you won't be disappointed at the U.S Hot Rod Association Spring Motorsport Spectacular Saturday at 8 at RFK Stadium. In addition to the mud-bog racing and manly truck and tractor pulls, L.A. stuntman Brian Carson will be on hand to re-enact the scene he performed in the film "Smokey and the Bandit III," when he drove a police car 60 miles per hour off a ramp and crashed it. Assisting Carson will be "Hill Street Blues" special effects man Marty Breslin, who'll detonate "pyrotechnic" devices hooked up to the car. With friends like that, who needs Mr. Goodwrench? Tickets are $12 and $15 for adults; $8 for children. They're available at TicketCenter outlets or at the RFK Box Office. 546-3337. Heel and Toe

From now through the summer you'll have a place to swing your partner to the sounds of live folk music -- every Sunday at 8 in the Spanish Ballroom at Glen Echo Park. Throughout the Sunday Night Dance Series, sponsored by the Folklore Society of Greater Washington and the National Park Service, expert callers will help singles, couples, beginners and experts step out the old-fashioned way. Admission is $5; $3.50 for FSGW members. 492-6282. Rest of the Best


The American College Theater Festival continues at the Kennedy Center with performances of "Idioglossia," a new play presented by the University of Utah in the Terrace Theater Saturday at 2 and 7:30. Then at 7:30 on Sunday, the festival's 12 regional finalists compete by presenting excerpts of their winning plays. Seating is available on a first-come basis; it's recommended you arrive at least 20 minutes before showtime. 254-3600.


The Washington Swing Dance Committee sponsors a dance with the big-band sounds of Doc Scantlin and His Imperial Palms Orchestra this Saturday at 9 in the Spanish Ballroom of Glen Echo Park. There'll be a foxtrot workshop at 8. Tickets are $5; singles are welcome. 229-4188.


There'll be plenty of barbershop music Friday and Saturday at 8 in two performances by the Alexandria Harmonizers Barbershop Chorus and the quartets Vaudeville and Copyright 86. The shows are at T.C. Williams High School, 3330 King Street in Alexandria. Tickets are $6 and $9. 248-8383 . . . Sunday is Loudoun County Day at Oatlands Plantation (on U.S. 15 six miles south of Leesburg). From noon to 5, there'll be live string bands, Scottish dancers, puppets and sheep-herding demonstrations. Admission is $4 for adults; $3 for children and seniors. Loudoun County residents are admitted free. 703/777-3174 . . . National Symphony Orchestra member Andrew Litton conducts the Arlington Symphony in a free concert of Strauss, Rachmaninoff and Tchaikovsky this Sunday at 3 in Kenmore Auditorium, 200 S. Carlin Springs Road, Arlington. 739-2903.