First, test your battery to make sure it has a full charge and can hold it. When you plug into shore power, does the battery charge?
Then, check to see if you have lights when not plugged into shore power. If so, then it could be your converter is shot.
If you don't have power to lights when not plugged into shore power, then you might have a shut off switch (usually located near the house battery).
When you're plugged into shore power, are your outlets live? If so, then there's probably a cutoff switch. If not, then you might need a new charger/converter - especially if the battery won't charge when plugged into shore power.
1975 American Clipper RV with Dodge 360 (photo in profile)
1998 American Clipper Fold n Roll Folding Trailer
Both born in Morgan Hill, CA to Irv Perch (Daddy of the Aristocrat trailers)