both potential issues have already been mentioned (circuit breakers on generator or transfer switch / manual cord transfer). here is a test to perform. unplug from shore power and start the generator. then test a couple of the 110 volt outlets (use a lamp, radio, tester, etc). do you have power in these outlets? if yes the generator is supplying the power and the transfer switch is working. if no, check / reset the circuit breakers on the generator. still no power, you have to determine if you have an automatic transfer switch or not. find the output power cables from the generator and trace them to see where they go. they will either go into an automatic transfer switch along with the input from the shore power cable. or they will go to an electrical junction box with a power receptacle on it that is the same as the receptacle on the pedestal that you plug the shore power cord into. if you have this you need to plug the shore power cord into this receptacle to get power from the generator. of course it could be something else but these are the most probable and easiest things to check.