You need to pick up a RV30A(M) to 50A(F) LONG ADAPTER like this. Think I saw one at WALMART. AMAZON has then for sure...
NOTE the two HOT PINS are tied to together to feed both 50A 120VAC ZONES in your trailer.
With both 120VAC 50AMP ZONES powered up you will be not be able to run two high wattage appliances at the same otherwise it will trip the 30AMP PEDESTAL CIRCUIT BREAKER.
Just watch what you have running.
This ADAPTER is another good item to always have with you when camping. You never know when you might find another camp ground that only has 30AMP Connections.
If you pick up another RV30A(F) to 15A(M) LONG ADAPTER then you can plug into a standard 120VAC 15A/20A RECEPTACLE at the house/garage and run both of your 50AMP trailer ZONES with 15A/20A SERVICE. Same things here about running two high wattage items at the same time...