If there's no contract involved, they can terminate you for any reason or no reason at all, unlawful discrimination excepted. You give no indication of anything that makes me suspect unlawful discrimination, so the fact is, they probably can let you go for no reason.
But you can consult a Florida employment lawyer who can give you legal advice based on all the facts and circumstances of your case. Maybe he or she would come to a different opinion. I'm not licensed in Florida so don't take my analysis of what you say as legal advice.