If you aren't receiving any channels you may need a DTV converter.. Maybe it has to due with signal strength but I get more channels by using a DTV converter and leaving the TV on channel 3 than I do by using the tuner in the TV.
It's on a state by state basis. Generally speaking many rest areas do not allow overnight camping. If you are pull in at 10 pm and are on your way by 6 am, don't drop your jacks, extend slide-outs, etc. nobody will say anything. Most Walmarts and Cracker Barrel restaurants. In fact, some CB's even have RV parking. Be safe.