Where Can I take A Jon Boat Saltwater fishing in FLorida?

I am from Polk County, Florida. I am looking for a place to take my 12ft Jon Boat fishing. I have a trolling motor and 5hp Outboard on it. I know it is a small boat so I am looking for some flats or backcountry. I do not know too much about saltwater fishing, but I am an avid freshwater fishermen. The more details you can give me the better. If you could tell me exactly where to put the boat in that'd be awesome. Also, I do not know much about tides either. How deep are flats when it is high tide, and how deep are they in low tide? Thanks for your help.