Florida will be FAR FAR cheaper than San Diego for basic living. If cost is a big factor, Florida.
San Diego does not have the hot / humid of Florida. If that's a problem for you (keep in mind, you'll be in airplanes generally without air conditioning), I'd go to San Diego.
If you like nightlife, any of the major cities in Florida will probably be ok, as is San Diego.
Southern California will have a greater number and variety of airports than Florida (6600 feet elevation Big Bear, below sea level Thermal and Furnace Creek). Everything in Florida is sea level plus a handful of feet. No alligators in California.
If you like warm ocean water... Florida. I learned to fly in southern California 24 years ago, but I've flown a piston plane in Florida also.
Tony
San Diego resident