Everything you need, just not close to other things
Magnolia Springs State Park is a nice Georgia State Park. Located just north of Millen, GA, the park offers ample camping for both RVs and tents.
Spots are flat and easy to park campers and set up tents with enough room between each for a bit of privacy and a few walk-in tent sites for increased privacy. Cabin rentals are available as well as a group lodge. There is a bath house in the main campground that is well kept complete with flush toilets and showers, as well as a coin laundry machines.
Kayak, canoe, pedal boat and bike rentals are all available from the visitor center to explore the spring fed lake and mostly flat trails in the park.
This is a lovely park to camp and spend time in, but is a 2-3 hour drive to Atlanta or Savannah if you are interested in exploring GA. The town of Millen has fast food options, as well as ample opportunity to pick up essential goods.