Looks like your question is answered. I see you have a Greyhawk, so you have multiple options of getting power to your 120V outlets.
As Grumpy stated, have your shore power cord connected to an external power source, such as a CG power post, or maybe to an outlet at the garage.
Your Greyhawk has an onboard generator. Fire it up, and there is an auto transfer switch, that will provide power to all your electronic devices. Many people drive with the generator on, so you can use the rooftop AC system during the hot summer months.
Lastly, you have a 1000w inverter attached to your battery bank. This will only be connected to a few outlets (at best). Such as a residential frig, maybe to your entertainment center. The inverter can drain down a OEM battery bank fairly quickly. There will be a on/off switch located somewhere in your MH, for this feature.
Back to shore power, it is common practice at CGs to turn off the circuit breaker before you plugging in or unplugging. I always leave the circuit breaker at camp turned off when I leave. Most of the time when I arrive I find it turned off.
Have fun with your new Greyhawk