Check all of the circuit breakers in the 120 volt panel. Turn them completely OFF and then back ON.
With the circuit breakers off and NO power to the trailer ( unplug it) check for lose connections at the circuit breakers and the neutral buss (where the white wires connect) as well.
Look at all the outlets. Perhaps a PO installed a GFIC and it is tripped. I don't believe this coach came with GFIC breakers. But there may be a chance that someone installed one and it has tripped.
Knowledge: "A gift to be shared. A treasure to receive."