To the OP, welcome to the Forum.
If this was first time out, was your trailer winterized? Is there any chance the bypass system was engaged such that NO water was in the water heater?
If that was the case you may have a problem.
Double check that there is water in the heater by lifting the pressure relief valve at the top of the tank outside. You can do this when hooked up to the water supply or with your onboard pump operating.
If water comes out, then you are OK and it is a question of what was switched on (or not).
If you have no water then there is a very good chance you have blown the element I'm afraid.
Double check and come back to us.