Since you're in Largo, you've got a lot of great choices for Autocross. FAST (
www.drivefast.org) runs 2 events a month year round. They run at Brooksville Airport, Tampa Greyhound Track, and Tampa Bay Downs horse track. SCCA, PCA, BMWCCA, and Florida Corvette Racing Club run at Brooksville Airport also.
Gulf Coast Autocrossers run about once a month at Buckingham Field in Ft. Myers. They're not the best organized crew, but it's one of the best sites in the Southeast. 400 ft. x 2700 ft. of really grippy concrete.
SCCA and Martin Sports Car Club also do two events a year at Sebring.