The first regional Child Safety Day makes its debut this Saturday at 17 locations around the area. Sponsored by the Metropolitan Washington Council of Governments and area police, the day provides an opportunity for families to learn important safety tips and for parents to have their children fingerprinted and photographed. And it's all free. For exact locations and times of the program nearest you, call 223-6800 or your local police department.

The following events are free unless otherwise noted.

NATIONAL ZOO -- Open daily; gates open from 8 to 8; animal buildings, 9 to 6; panda feedings, 11 and 3; elephant training demonstrations, 2; sea lion training demonstrations, 2, 3001 Connecticut Ave. NW (Rock Creek Park), on the Metro Red Line. Family learning centers Zoolab and Birdlab open Friday through Sunday, noon to 3; Herplab open Wednesday through Sunday, noon to 3. 673-4717.

OXON HILL FARM -- Open daily, 8:30 to 5, Oxon Hill Road (take Beltway exit 3A, turn right on Oxon Hill Road). Saturday, 11 to noon, barnyard, join a farmer to shell and crack corn for poultry feed. Sunday, 2, hayride; reservations required. 839-1177.

NATIONAL AQUARIUM -- Open daily, 9 to 5, Department of Commerce, 14th and Constitution Avenue NW. The sharks are fed Monday, Wednesday and Saturday at 2; weekday features are a touch tank, mini- theater and a thousand types of marine life. Adults $1; children 50 cents. 377-2825.

CEDAR HILL -- Open daily, 9 to 4, 1411 W St. SE, Anacostia. Cedar Hill, Frederick Douglass' home, recalls his work with films, interpretive exhibits and a house tour. 426- 5961 or 426-5962 or 426-5963.

USS BARRY -- Open daily, 10 to 5, Washington Navy Yard, Ninth and M streets SE. The Navy destroyer's weather deck is open for public viewing and self-guided tours. 433-3377.

CHILDREN'S MUSEUM -- Monday through Saturday, 10 to 4, Sunday 1 to 4, Rose Hill Children's Museum, north of Frederick, Maryland. Take U.S. 15 north to Exit 8 to Motter Avenue; follow Motter to left onto 14th Street and left onto North Market Street, follow signs to Rose Hill. Saturday, noon to 4, Halloween costume party for children eight and under. Sunday, 7 to 9 p.m., pay a visit to a haunted house. 301/694-1646.

CAPITAL CHILDREN'S MUSEUM -- Daily, 10 to 5, 800 Third St. NE. Make your own pumpkin with yarn, newspaper, paper bags, tissue paper and other materials supplied by the museum. Friday, 10:15 a.m.; Saturday, 1 and 2:30; Sunday, 2:30, "Peter and the Wolf." A marionette version of this classic Russian folktale. Museum admission $2; special performances an additional $2. 543-8600.

DOLL'S HOUSE & TOY MUSEUM -- Tuesday through Saturday, 10 to 5; Sunday, noon to 5, 5236 44th St. NW. A collection of antique dollhouses, dolls, toys, games and an exhibit of antique cat games and toys. Adults $2; under 14, $1; group rates available. 244-0024.

NATIONAL COLONIAL FARM -- Tuesday through Sunday, 10 to 5, 3400 Bryan Point Rd., Accokeek. Sunday, 1:30 and 3, learn about the legends behind your favorite herbs. Adults $1; children under 12, free. 301/283-

DISCOVERY THEATER -- Tuesday-Friday, 10 and 11:30 a.m.; Saturday, 1 and 3, Discovery Theater, Arts and Industries Building, 900 Jefferson Dr. SW. Classic Stories, Enduring Tales: "The Ugly Duckling." A puppet-production of the Hans Christian Andersen tale; recommended for pre-kindergarteners through third grade. Adults $3; 12 and under, $2.50; group rates available. For more information and reservations, call 357-1500.

CLOISTERS CHILDREN'S MUSEUM -- Wednesday through Friday, 10 to 4:30; Saturday, 12 to 4, 10440 Falls Rd., Brooklandville, Md., Saturday, 1 to 4, "Halloween Party and Parade," games, refreshments and costume party; come in costume. "Indian Summer Celebration." Hunt bear and porcupine hidden along a nature trail, dance around a totem pole and see an extensive Kachina doll exhibit. Saturday, museum hours, "Indian Crafts": decorate Indian headbands. $2 donation requested from adults; group tours available. 301/823-2551.

RAILROAD STATION MUSEUM -- Wednesday through Saturday, 11 to 4; Sunday, noon to 5, Main Street and Maryland Avenue, Ellicott City. The renovated station has a diorama of the trip of Tom Thumb (an early 19th-century train) from Baltimore to Ellicott City. There are also sight and sound shows, model train exhibits and tours of the museum. Adults $1.25; under 13, 75 cents. 301/461-1944.

COLONIAL FARM -- Wednesday through Sunday, 10 to 4:30, Claude Moore Colonial Farm at Turkey Run, 6310 Old Georgetown Pike, McLean. Take a self-guided tour of farm life for a low-income family in Colonial Virginia. Ongoing demonstrations of agricultural and domestic chores, such as spinning and candlemaking, round out this history lesson. Adults $1; children under 12, 50 cents. 703/442-7557.

CHILDREN'S RADIO THEATER -- Saturday, 8 a.m., WPFW 89.3 FM. "Scary Tales," chilling Halloween stories. Listeners can participate in a call-in following each program by calling 783-3104.

SATURDAY MORNING AT THE NATIONAL -- Saturday, 9:30 and 11, Helen Hayes Gallery, National Theater. Chris Patton presents, "Benji's Halloween," a modern folktale with live, computer-generated music. Reservations recommended. Call 783-3372, 24 hours a day.

BABY AND CHILDREN'S BAZAAR -- Saturday, 9:30 to 11:30, Montgomery Village Junior High School, 19300 Watkins Mill Road, Gaithersburg. Children's clothes and books for sale. 652-5383.

DISCOVER THE GALLERY -- Saturday, 10 to 11:30, National Gallery of Art, Fourth and Constitution Avenue NW, "Sculpture: The Art of Three Dimensions." A program for families with children ages six to 12; see a film for kids, "A Boy Creates," about a boy who makes sculpture from junk; then take a tour of the museum. Free, but advance registration required. 842-6249.

HALLOWEEN HARVEST FESTIVAL -- Saturday, 10 to 3, National Presbyterian School, 4121 Nebraska Ave. NW. Children's fair featuring games, movies, pumpkins and entertainment. 537-9022.

FUN FAIR -- Saturday, 10 to 2, Gunston Elementary School, 10100 Gunston Rd., Lorton, Va. Tethered hot-air balloon rides, games, prizes, haunted house, food, auction and crafts. 339-8065.

TOY AND BOOK STORE -- Saturday, 10 to 3, 11931 Seven Locks Rd., Rockville. Bake sale, petting zoo, toys, books, rides, games. Free admission, but tickets are $2.50 to see Bob Brown's "Monster Madness" puppet show. 340-7704.

TROLLEY MUSEUM -- Saturday and Sunday, noon to 5, Northwest Branch Regional Park, Bonifant Road between Layhill Road and New Hampshire Avenue, north of Wheaton. Trolley rides: $1 adults; under 18, 75 cents; under two, fee. 384- 9797.

CHILDREN'S PLANETARIUM -- Saturday and Sunday, 1 and 4, Rock Creek Nature Center, 5200 Glover Rd. NW. First show for children four to seven (must be accompanied by an adult); second show for ages seven and up. No latecomers are admitted. 426-6829.

ADVENTURE THEATER -- Saturday and Sunday, 1:30 and 3:30, Adventure Theater, Glen Echo Park, Glen Echo. "The Magic Flute," a one-hour marionette version of Mozart's opera, featuring dragons, flying horses and enchanters. $4, group rates available. 320-5331 weekdays and performance days from 10 to 2.

CHILDREN'S FLEA MARKET -- Sunday, 10 to 2, Wheaton Park Shopping Center Parking Lot, 1209 Georgia Avenue (at Shorefield Road), Silver Spring. Children's books, clothes and toys and baby equipment. 984-2323.

PRINCE WILLIAM FOREST PARK -- Sunday, 1, Park Headquarters, near Quantico, Va. (from I-95, take Exit 50-B, Rte. 619 west; follow signs). Join a ranger on a hike to see an active beaver site; 3 p.m., park Nature Center, join a ranger to learn basic compass and map skills; for kids six and older. 703/221-2104.

BLUE SKY PUPPETS -- Sunday, 2, Rock Creek Nature Center, 5200 Glover Rd. NW, "Lights Out on the Bunny Brothers." A 45- minute presentation featuring singalong, music, puppet show and other entertainment relying on audience participation. 426-6829.