There is plenty of camping throughout the Fort Valley Trail Head area.
There is room for RVs off of the paved section of old highway along the beginning or FR164B.
There are other camping options up the mildly bumpy FR164B road, and a bit up the FR9002 road about a mile in on the right, just before the cattle guard. (High clearance recommended if you go up FR9002.)
Please do not park or camp at the Fort Valley Trail Head itself.