Wednesday was the first day of dog obedience class for some 10- to 16-year-olds and their pets. Two St. Petersburg police officers teach the class from 9:30 to 10:30 a.m. every Wednesday through July 7 at Bay Vista Park. In this class, organizers have divided the program into shorter segments than in a usual dog obedience program. The cost is $8 for four sessions for St. Petersburg residents, plus $2 for a city Recreation Department registration card. Non-residents must pay an additional $2.40. Those interested may join anytime. For information, call 893-7124.