Hi, check out: Freecampsites.net
Cracker Barrel is your best bet for 1 nite. I am a Harvest Host Affiliate I use Boondockers Welcome (BW) with them for years now can stay 1 or 2 days. Harvest Host side a separate membership are overnights at businesses with a purchase. Here is a link if interested:
https://www.harvest-hosts.com/KQ2XCW/6JHXF/?creative_id=39
Im in Florida Keys now. When you get to Florida don't count on Walmart, many do not allow overnight parking too many have left messes & garbage.
If you are seniors the National Park Lifetime Senior pass is awesome & discounts camping at National Parks, Forests, Army Corp of Engineers. $80 or free to Vets or Handicapped. All Florida State Parks are full hard to get a reservation anywhere.
Safe travels....,