I was camped at Pocono Raceway the first weekend of June for the Pocono400. I was there from Thursday at 12noon until Monday at 12noon and I had a very good time. I was camped Trackside. Camped in the infield or outside the track you still have access in and out. There is a tunnel under the track to the infield. I do think it costs extra for that in and out privilege. I suggest you arrive with a full fresh water tank and empty holding tanks. All the food and drink you need. Propane tank full. Fuel tank full. There is holding tank emptying service available but there is no drinking water delivery service available. Sites are close together so I suggest having a Genturi generator exhaust system. There will be 24hr generator use and some 24hr parties. There will be a shuttle that circles through the camping areas that takes you to the infield concert/party on Fri/Sat/Sun nights. There is a daytime shuttle that takes you to the grandstand and the Fan Fair area.
Wear comfortable shoes.
Take ear plugs.
Relax.
Have fun.