are you on advrider.com? check around on that site for camping options in the outer-boroughs. always someone willing to help if you look hard enough.
i personally would not want to deal with the metro-north trains. if you are not to particular, you can find decently priced hotels in the city. you will pay for parking though and it won't be cheap. but not having to deal with trains, at least for me, is well worth it.
searching for hotels is not difficult. 3 friends of mine from nicaragua shared a room and although it wasn't the greatest, it cost them about 60 each per night.
as for food, whatever in the world you desire you can find in NYC. tell me what you like and i can recommend a few places.