The 120 volt circuit breakers you found in many Fleetwoods are next to the 12 volt DC distribution panel. If you have fuses behind a metal cover held on by a thumb screw that is the panel.
You said you reset breakers, did you push the breakers toward of?
there should be power to one of the sources, normally shore power.
Remove 120 volt breaker panel. Look for damaged wires. Check the white(neutral) in very back. Do this with genset off and shore power disconnected.
Use a meter or 120 volt test light to insure power is coming to the 30 amp main breaker. Could be a bad main breaker.