Best place to go is Fort Desoto Beaches. Absolutely beautiful!
Also, Clearwater Beach at Pier 60 before sunset they have a great celebration with street entertainers and crafts. Lots of fun for all ages!
Most museums close before 5pm and it seems that downtown rolls up then. Be very conscious of your speed in the beach areas, the police are!
Sorrento's on Tierra Verde has EXCELLENT pizza, calzones, and Italian food in general!
Best Way To Get Around:
Driving is fine, but there is a convenient shuttle up and down the beach and from downtown St. Pete.