There's a Walmart in Tifton but I wouldn't stay there and I have been to Tifton many, many times. There's a campground just past the AgriRama; it's under new management and I can't for the life of me think of the name but it's well advertised on highway. There's a Flying J at exit (29?) in Valdosta that's quite nice but you might want to get there early as lots of rv's stop for a rest there. You'll also pass lots of well advertised campgrounds off I-75 between Tifton and Valdosta, many of which are fine for an overniter.
Tony & Yolanda / Katie & Spencer (the Doodles)
2011 Fleetwood Revolution 42W (450/1250)
2008 Jeep Grand Cherokee (Diesel) behind