As any true, Washingtonian knows, it's never too early to think pigskins and Redskins. So this weekend why not take a few minutes to draft your game plan for a trip to see the team getting ready for the season. Sunday, the team's rookies check into training camp in Carlisle, Pa. And beginning Monday, you can watch their weekday practices for free at Dickinson College.

Or you can catch the first scrimmage, on Saturday, July 26, when the likes of No. 1 draft pick Marcus Koch and wide receiver Walter Murray test their skills against the New England Patriots rookies beginning at 1 at Mechanicsburg, Pa., just a quick down-and-out from Carlisle. Cost is $3.

Naturally, the vets get to saunter into camp a bit later (July 27). They join the rookies for a scrimmage against the New York Jets on August 2 in Easton, Pa. Tickets are $6 for that. The camp is closed to the public after August 2 (we told you you'd better make plans).

For more information and weekday training schedules, call Redskin Park at 703/471-9100 or the training camp office at 717/245-1140. Cartoon Concert

This is a first: Disney characters on tour from Anaheim -- including Cinderella, Mickey Mouse, Donald Duck, Pinocchio and Porky Pig -- teaming up with the National Symphony Orchestra. Together they'll fill the Capital Centre with such Disney classics as "When You Wish Upon a Star," "It's a Small World After All," "Fantasia" and "Supercalifragilisticexpialidocius." It's Friday at 8. Tickets, $12.50 to $18.50 ($5 less for children under 14), are available at the door or by calling 432-0200. Dance Fever

Dedicated followers of fitness know aerobics has become a serious team sport. And Saturday, 21 squads from as far away as Hawaii converge on the George Washington University's Smith Center to vie in the Third Annual National Aerobic Dance Championships sponsored by the Amateur Athletic Union. Competitors are judged on synchronization, choreography and aerobic technique. The preliminary action , is 9 until 2; the finals are at 7:30. Tickets for each session are $3; $2 for students ($1 for children). They're available at the door, 600 22nd Street NW. 569-9488 or 676-6388. For Those Likin' Spikin'

About two dozen nets will be strung up on the Mall for the Fourth Annual National Kidney Foundation Volleyball Marathon Saturday from 8 to 8 at Fourth Street and Independence Avenue SW (across from the Air and Space Museum). Spectating is free; individuals wishing to play can register on site for $10. The Montgomery Volleyball Association will be giving free clinics on serving and spiking throughout the day, and DC 101's disc jockeys take on the Redskinettes alumnae in a celebrity match at 2. Proceeds benefit the National Kidney Foundation. 337-6600. Key to the Keys The University of Maryland winds up its International Piano Festival and Competition this weekend. The festival finishes Friday with an all-Beethoven concert by Canadian pianist Anton Kuerti at 8:30 in the campus' Tawes Recital Hall. Tickets ($12, $10 for students and seniors) are available at the door. 454-5276 or 454-2201. Key to the Keys

Then on Saturday, the three finalists in the competition play with the National Symphony Orchestra at 8:30 in the Kennedy Center Concert Hall. Julius Rudel conducts. An awards ceremony immediately follows the concert; the winner gets $15,000. Tickets, $12 to $25, are available at the Kennedy Center Box Office. 254-3600. (WGMS 570 AM/103.5 FM offers live broadcasts of the Kuerti concert and the finals, beginning at 8:30 both nights.) Free and Easy

The city of Baltimore offers some hot free entertainment as part of its Artscape celebration, which is Friday from 6 to 11; Saturday and Sunday, 11 to 11. In addition to art exhibitions, crafts and food, there'll be continuous live music. Some highlights: Sara Vaughan, Noel Pointer, Stanley Turrentine and Jon Faddis hit the stage from 8 to 11 p.m. Saturday; Joan Baez performs Sunday at 8:30. Artscape is outdoors on Mt. Royal Avenue between Maryland Avenue and Lafayette Street. 301/396-4575. Rest of the Best IN TOWN Dance Explosion, an outdoor dance party hosted by the D.C. Society for the Prevention of Social Boredom, is Saturday from 9 p.m. to 1 a.m. in Parking Lot No. 5 of RFK Stadium. The Mixmasters spin a variety of music -- from Motown and Chuck Brown to the Beatles and Top 40. Tickets, $6.50, are available at the gate and include soda and beer. 966-2612 . . . The tall ship Shabab Oman sets sail Friday at 10 a.m. from Municipal Pier, while the Italian schooner Corsaro II arrives this weekend at Gangplank Marina, Fifth and Water streets SW. The public can board the ship Saturday and Sunday from 3 to 6; it'll be in port until July 25. Free. 387-8292. IN MARYLAND

The NASA/Goddard Space Flight Visitors Center in Greenbelt holds it Sixth Annual Model Rocket Tournament Sunday at 10. Spectating and on-site registration are free. 286-8981. IN VIRGINIA

The Virginia Estate, Stable and Wineries Tour is Saturday from 9 to 4 in the area around The Plains, Middleburg and Upperville. The 10-stop tour includes Atoka, the estate of Senator John Warner. You can begin the tour and get your tickets ($12) at The Paper Chase, which is two miles east of Middleburg on U.S. 50. 703/592-3610 or 703/592-3848 . . . Woodlawn Plantation throws an old-fashioned picnic Saturday from 4 to 8. Entertainment includes carriage and tethered hot air balloon rides, turn-of-the-century music, croquet and other games. Ice cream, watermelon and beverages will be for sale. Tickets -- $5; $4 for children -- are available at the door. The plantation is at the intersection of U.S. 1 and Route 235 in Mount Vernon. 557-7881.