The only goofy questions are the ones left unasked!!
You shouldn't roll down the road with the heater lit. It won't stay lit as it's not designed (in most campers) to do so. How you light the unit will depend on your make/model. Some will require you to manually light, which is pretty much the same as lighting the hot water heater in the house. Others will have a nice little switch that will do all of the work for you and should be clearly marked somewhere in the camper.
A word of advice - as I wasn't aware of this during my first trip - make sure the water heater bypass valves are in the correct position, otherwise you'll have no hot water and possible pressure issues!
Best of luck to you, and have fun!!