Replying to Essentials for car camping

I live in eastern va and plan to be up every weekend at some mountain or another this year. I plan on mostly car camping so I need to know what I will need for it. at the moment I know i will need a sleeping bag and maybe a pad but any other essentials?

i work monday through friday so i will have to leave from work and essentially go straight to the mountain every fri. night and come back sunday. I don't really have any camping gear right now except the car and a nalgene right now.

Are resorts on the east coast cool with people sleeping in their car in the free lot over night?