Take the Old Town Trolley Tour.
Hop On Hop Off Sightseeing Tours with Old Town Trolley Tours. You can get on and off at the various stops.
If you like old churches, visit the Roman Catholic Cathedral Basilica of St. Augustine. Built in the 1790's, it is the oldest church in Florida.
Restaurant recommendations: Florida Cracker Cafe, Harry's Seafood Bar & Grille and Hurricane Patty's Bar & Grille.
Really enjoyed St. Augustine.