1) yes they have refresher courses. Google it. Also you can save money and YouTube tips and practice on your own (ideally with s buddy)
2) My favorite BCD is the TUSA wing style BCD. It has pockets like a vest but the air is all behind you. It’s really good- excellent reliable inflator and deflate valve, integrated weights with quick release, good quality durable material etc. I got mine for only $260 and it was a bargain.
3) Florida is awesome for spear fishing. California is too liberal and Nazi esque