Is your interest to live aboard simply to use the boat as a house or to actively cruise using the boat as your transportation and housing? If your only looking at being in a marina environment then South Florida would be a good choice.
If your looking more at actively cruising then the Caribbean would probably be a better choice to get a feel for the life in a relatively safe environment but not being a marina barnacle collector.
The style between always being at a slip vs being on the hook or mooring are Totally Different life styles and you will not learn much from one to use in the other.
I prefer a sailboat to a motorboat, and it is my belief that boat sailing is a finer, more difficult, and sturdier art than running a motor.... Jack London