Other than the awning, what else on the 12-volt system doesn't work? Is the battery switch OFF? Typically the awning is operated from the 12-volt system and, other than to charge the batteries, shore power is not needed for the awning.
The microwave, and/or the air conditioner both draw lots of power and are dedicated to only shore power operation.
The onboard converter charges the batteries and supplies 12 volts of DC to the systems, i.e. water pump, lights, furnace fan, etc.
The inverter, if supplied, is converting 12 volts DC to 120 volts AC for such items as TV and a limited number of outlets.
Bob