you should look at colleges instead of locations.
This was going to be my suggestion as well, as it seems you're putting the cart before the horse here. Do you have any idea what you want to do with your life? I mean, I've seen a list of professions, none of which have anything in common with the other. For example, if you plan to supplement your income in between classes with lets say....oh, construction or landscape...area's with high snow fall in the winter months wouldn't make a good choice as there would be little work for you. This type of work is seasonal. It seems much more practical to be thinking long term here. Decide on at least a "general" major, seek out stellar schools that will give you the real training you need, and spend 4 or 5 years making something of yourself. Many colleges offer job placement assistance for their graduates. With an education, you will have much better luck moving to your dream destination and making it work. And before you get in a huff, I know you are planning on college so "education isn't the issue", but it really is.
Here is a tidbit. Besides cost of living, take a look at the job market in these places. Tennessee has one of the worst job markets around (DH is from there and we have lived there) and depending on the area of TN you look at, it is not gay friendly. We lived in NE TN....right in the smack middle of the bible belt. I am heterosexual and DH and I were living together before we got married...a mortal sin there. We had a very difficult time finding someone to rent to us. As others have said, just because it's legal to rent to an 18yo and illegal to not rent based on sex, ethnicity, sexual orientation....it doesn't mean it doesn't happen.
Dreams are great to have. If someone doesn't have a dream of some sort, they don't have much. But don't set yourself up to fail. Get your priorities in order. If FL is what you have to have, do you want it at the price of living there, but not ever really being able to LIVE there? All the planning on room mates and jobs and apartment prices in the world wont make them come true. There are no guarantee's in life. Set yourself up for sucess at every turn so that giving up and moving back to mom's never has to be an issue.