Take the trolley tour. You can park your car at the jail and take it from there. Do the distillery tour and ask to sample the gin they make - ask for it neat. They also have a winery tour with sampling afterwards. I'm not much of a fan of their wine, but others like it. You can get off the trolley at both places. Near the disilery, there is a nice restaurant called The Icehouse - think it's part of the distillery come to think of it.
Not knocking Anastasia, but North Beach Resort is much better - check it out for future trips - huge private sites with full hookups. There are some nice restaurants in that area on the inter coastal - Caps and Aunt Kates. It will be cool enough to dine on the outside decks.
If your in shape, climb the stairs at the lighthouse for a great view, but at least tour the museum.
Don't remember the name of this place, but there is a seafood restaurant at the end of a pier by the bridge of lions. It's awful - don't go.