I say go for it Si! If you don't you might regret it later and become despondent thinking about all the "what ifs". You won't be alone since you'll have your parents and I'm sure you'll make friends in no time (my secret sources tell me that Americans go wild over English accents
).
If you have a clear idea of what you want to do (for example, become a personal trainer) then it doesn't matter where you do it as long as you follow your dream. It does sound like you need a change of scenery if your present surroundings feel like a "dump" - and Florida is anything but that!
I know it's a bit overwhelming to consider such a big change (my parents moved from England to Canada where they didn't know a soul), but if you sit down and weigh the pros and cons of such a move and the "pros" are ahead, then come on over!