You may want to do a little research on what is 12V and what is 120V in your RV. Sounds like your 120V breaker(s) have tripped - or the breaker on the pedestal (or wherever you are plugged in). In either case it would be good to find out why. Sounds like the lights and control panel (which work on 12 V) are working fine. Typically, your outlets and large amp draw items like the AC and microwave run on 120v. Shore power or generator supply 120V. Your lights, panel, water pump etc usually run on 12V which is supplied by your house batteries. It's possible that your friend may have tried to run too much on the 120V system - like running the microwave and AC at the same time. Knowing your electrical systems as well as power management is something I would put on the short list of things to learn.