Well I probably don't have to tell you that going in cold to an area is tough to say the least but I'll throw out a couple of ideas. On East Lake Toho there is a boat rental outfit- I haven't been there for a while but I'm pretty sure it's still there. Now a days probably around $60 to rent a 15' fiberglass with 5-10 hp motor.
E. Lake Toho is a round, shallow lake. You can troll a plastic worm, cast, or fish shinners under a float.
Another boat rental is on the St. John's River- Highland Fish camp. The surrounding is a bit more "Florida"- that is a river w/o any houses, etc and the cost about the same. On the river I'd cast, maybe shinners in the deeper bends, etc.
Hope the two leads help- at both outfits they ought to help suggest what's best in their area, etc.
Tarpon- closest to Orlando that's really famous is Port Charlotte- gets crowded from what I hear. May is when you want to be at Port Charlotte.