ive never done a timeshare but there are multiple apt listings you can find in the jewish press etc to rent an apt. most have pictures and will give you references to call
I would be very careful with timeshares, the satisfaction rating for them industry wide is about 8% and they are basically unsalable once you buy them. Really avoid the things.
I never heard of a timeshare in Miami Beach. If you find one, it most probably won’t be where you want to be. You can get great deals right now in the Frum areas so you have everything covered.