To follow up with what others have said it depends on what kind of system you have. Here is a diagram that shows a standard spotsmobile with a power converter.
As you can the power converter plugs into an outlet that is wired into the wall receptacles. That receptacle may be a GFI version or will be downstream of a GFI receptacle. If the GFI has tripped you have to make sure you have power to the GFI receptacle in order for you to reset it.
In the case of an inverter/charger you have a differnet setup.
Because the inverter has an internal transfer switch the 30 amp shore circuit goes directly to the inverter and from the inverter to the 30 amp breaker on the 110 distribution system. Note, they still show a power converter in this diagram, but you should not have it. In this case there are most likely circuit breakers that need to be reset on the unit. If you can identify the unit, I can most likely help out with which one it may be.
I suspect you have a converter and the GFI is the culprit, you can always get one of these
at your local home depot to test your outlets. If you have a converter the easiest thing to do is use a good extension cord and unplug from the van and plug directly into extension cord from your house. If it now starts to work , you work backwards from there.
hope this helps