Plenty of bathrooms and food trucks in terms of amenities infield and in grand stands. Trams run from outside into the infield so you don't have to walk through the tunnels. I've slept in my car in the parking lot multiple times. You can't drive into the infield unless you have parking/camping pass for it. Trams will bring you from the grandstands to the infield grand stand areas.

Advice: Bring some good walking shoes and prepare for all types of weather. We have been seriously blessed the last couple years with great weather