I agree that you need to do a lot of research before you even consider purchasing, even if you've been to Disney multiple times. Sit and read about how the points work, what they can be used for, the timelines for usage and booking, resale restrictions, how many points you need for a typical vacation you might want to take (do some sample vacations to see how many points you would need to book), and learn about the dues and possible payments if you're financing and whether you can really afford that. And then sit some more and look at all the resorts individually and what they offer and what room types they offer, where they are located, what transportation each has, amenities,
point charts compared to the others, etc., with a map of Disney World as reference. There is a lot to learn unless you're an old hat at
Disney vacations, and even then it's different than the cash rooms. After doing a lot of research, pick a couple resorts to visit to see if you would really want to stay there consistently, and then go from there.