Start by resetting the breakers. Turn them all off applying light force toward off. Turn on main breaker if equipped, then turn on branch breakers one at a time.
No power!
Reset the pedestal breaker as described above.
Try plugging a portable 120 volt item into the receptacle in the pedestal using an adapter.
Power!
You could have loose connection in the rig, hard to identify with out meter. Could a loose screw in the back of the 120 volt breaker panel. Disconnect from shore power, remove cover over breakers, tighten screws in the back on the white wires (neutral). Locate the large #10 wire feeding the main breaker and tighten it.
Still no power? Get some help!