The Withlacootchie is a long ways in. (6 miles in channel from the gulf to the mouth). Shorter for overnight would be the greenway, (Cross Florida Barge Canal) which is very sheltered and has a boat ramp and ranger station. Resupply would be a fair walk though from either place. However Yankeetown and Inglis are pleasant places to visit. Well marked but a bit confusing as there are three branching channels.
A plus for a beginner is that you can see either the stacks at Anclote or the cooling towers at Yankeetown for the whole 50 miles making it a piloting rather than a navigational event.