If you are getting the 110VAC for the A/C...(lights are 12VDC system), then you are probably getting the power from the generator, so it may be a tripped breaker or even the GFI outlet in the bathroom that may have tripped.
Check to see if you are getting voltage at these outlets.
If the A/C is not working, then you could very well have a problem with the transfer switch, the generator, or how you have the system set up (as mentioned above, some units require you to plug the shore power cable into an outlet from the Genset).
Good luck