If you have a shore cord, you must have a breaker panel that splits the power to different circuits. If you have a generator, you must also have some way to switch between the shore cord and the generator power. The simple way is that the generator has a cord that plugs into an outlet that the shore cord can alternately be plugged in to. They must not be both plugged in at once, it's a law to prevent back feeding the power to the pedestal. Most modern RVs have an automatic transfer switch that switches from one source of 120 v AC power to the other when present.
Try to follow the shore cord into the RV and look in closets, swing open doors, etc. to find your circuit breaker panel. Your breaker panel also power your converter/charger that takes the 120 v AC and converts it to 12 v DC for your lights and appliances. In addition, it keeps your batteries charged. Again, if wired in the 'best' way, the charger will keep both your house and chassis batteries charged when plugged in to 120 v shore power. In addition, it's nice when the engine alternator also charges the house batteries when the engine is running. You can check for this function by taking voltage readings at both battery groups when unplugged and then again when plugged in. If charging is present, a voltage increase will be detected.