We need more info. Things to try..............
!. Your slides are 12V so a totally dead battery could be part of the problem but, I assume that when you plugged into shore power that you checked to make sure that the breaker was on at the pedestal ?? Is there power to the campground pedestal ?
2. Have you tried to reconnect your tow vehicle to see if the slides would open while connected to it?
3. Is your trailer battery dead or ? Did you check to see if there is a fuse or reset coming off the battery under the tongue?
4. What type / model camper do you have ???
Good Luck !