You also might want to check out your local bookstore. They will have motor home and rv magazines that were very helpful when we bought ours. They do great research on many camper issues and campers themselves give great tips. Another great place to visit while in the Orlando/Tampa area is Lazy Days. THey are about 45 minutes from WDW and they have the most RVs and Trailers I have ever seen. They are really nice and you are free to roam the acres of equipment. We really liked that they let us drive some of them so we knew what it was like. We still go over there sometimes and camp, they even give us free lunch on certain days. We have had two Winnebagos and a Coachman 24 ft trailer. The trailer was nice but the tanks were not big enough, hated the hooking and unhooking process and trying to get the trailer level was a hassle. Probably the scariest part was the driving. We pulled it with an Expedition and even with sway bars it was tough to keep control of it (wind & trucks). So try to get some driving time on the interstate to gage if this is something you can handle, it can be very scary. The sales man even said that after a year we would be back to trade it in. Two years later we did.
Most campgrounds have water, sewer and electric. Some have cable and many are adding telephone outlets so you can connect your computer. As for tank size the more people you have the larger the tank you want. FW has all of these hook ups except for the telephone.
Suggest you do a lot of research really do a lot of reading, visit many rv shows and dealerships before you make a selection. It is like buying a second house. We love our camper and feel FW is the best campground around. I also have to say that campers are the friendliest and nicest travelers around. We also get suggestions and in great conversations with fellow campers wherever we go. It is something I have never seen elsewhere, must be a camper kinship.