Welcome home and thank you for your service.
I would not worry about fuel in just 4 months. But since has been sitting a extended period of time after you start it for the first time let it sit and warm up good before you move it, since there is 0 oil residue left coating the cylinders and valve train. In a automatic if sitting and running for a few minutes shift it in neutral and set the brake while you let it sit, I am sure this transmission would be fine but I have seen other automatic transmissions get excessive wear from sitting in park running for a extended periods.
Best R&R is a curvy road with a few good straights and no traffic.