I retired in 2003 after spending 30 years in construction/real estate/mortgage banking. I also owned a campgrounds, canoe rental & horse motel in Lebanon, Missouri on the Gasconade River back in the 1980's. I headed out in the lap of luxury in my retirement gift of a Toyota Motorhome prior to 60 yrs tent camping. I have been rescuing retired Champion Keeshond dogs for over 30 yrs.
I can recommend tents that are good. I'm good with computers. I know mortgage banking. My hobby for 25 yrs was obedience training dogs.
In Florida ... Dinner Island Ranch, east of Immokalee. It is a Wildlife Management Area. I can't go there because dogs are not allowed but many RVers I know love it there. http://myfwc.com/viewing/recreation/wmas/lead/dinner-island/visitor-information/ I understand from a frequent campers that there are two campgrounds here; Campground A is a wide open field, roughly 6 football fields wide, open grass (not well mowed). Campground B is in the trees with a brand new concrete block one outhouse next to a paved handicap site. It is not really for large motorhomes other than the handicap site. Horses are allowed.
Also, in the same area check out ... Okaloacoochee Slough Wildlife Management Area
In Missouri ... I camp at Loggers Lake in the Mark Twain NF, 7 mi S of Bunker, MO (Hwy 72). It is a fee area but for Seniors it's $4 a day, cheap enuff to be called free. Been camping there yearly since 1962.
21 ft Class C Toyota Motor Home