Are you going to take a drysuit course or have someone show you the ropes? If so, they will probably go through all of what others have said. Incidentally, I'm pretty surprised you have been diving wet all this time in the FL caves. I'm not cold tolerant at all.
I don't know if it's standard procedure, but I always do a p-valve check after suiting up. That is, walk off to the side of the parking lot, put your hands on your hips as though in deep thought, and let 'er rip. Everyone will know what you're doing, of course. And then as part of our pre-dive check, we include "p-valve hooked up/tested."
Also, plan how you're going to clean/flush the p-valve and what you're going to flush it with. If you're using a quick-disconnect, plan for how to connect the squeeze bottle or whatever you're using. Some people use vinegar-water solution, some do Steramine or other sanitizer, some give it just a quick flush from a squeeze bottle, some flush from a garden hose for a full minute, etc. From reading others' experiences, assuming they are honest about their success in preventing UTIs, my conclusion was that the type of solution and amount of time make less difference than simply making a habit of doing it after each dive day.