Definitely vistit the state parks. Gold Head state park is a quick jaunt down 21. Also visit the beach in Keystone if you have kids. There is always a local festival or 2 or 3 in the area.
The state parks are great for hiking. Gold Head state park also has reasonably priced accomodations, most of which include kitchens. It's a great alternative to staying with relatives or out of town in Starke or Gainesville.
The Melrose Cafe does not look like much from the outside, and the decor is not impressive either. But that is not what the cafe is about. They serve good portions of downhome southern country cooking. The place was packed and everyone seemed content. The wait staff was friendly (this is one of those places where all the customers are greeted by name or with "honey") and efficient.
Favorite Dish: I was tempted by the spagetti but opted for the Fried Catfish. Good choice it was very good and a nice sized portion.
For a true taste of local culture, go to Chiappini's. It is a bar/gas station/ammo/bait establishment. It closes early, but is a true slice of redneck life.
Don't miss the taxidermy. This is a strange place.
Take the train to Palatka (unless you want someone to meet you at Waldo around 3am). Hopefully, the trains will be running and on time. Then drive. Someone must meet you. Taxis are virtually non-existent.
You might be able to get a flight into Gainesville, FL. If not, Jacksonville is next closest.
Must have access to a car.