Hoping the converter/charger was not turned off by flipping its 120VAC breaker when you hooked up to the house 120VAC Receptacle... The converter/charger being run from the 30AMP Shore Power cable is what was suppose to run your 12VDC items including the water pump as well as charging your on-board battery. Actually the charged up battery would have run your water pump just fine if it was connected to your 12VDC Distribution Panel not required to be hooked up to Shore Power.
Also hope you had all three conductor of the shore power cable connected to your house 120VAC 15A receptacle through the approved type RV30A-15A adapter..
Whenever we hook up to to shore power we always do a quick check with a DC MULTIMETER across the battery terminals to see if it is getting a charge from the converter/charger unit when hooked up to shore power. The battery terminals will read 12.6VDC when fully charged and will jump up to 13.6VDC if it is connected to the converter/charger unit if it is working...
Lots of things to learn about how the trailer works to keep ahead of situations...
Roy Ken