Plugging in to 15 amps should give you enough power. Sounds like the battery is dead as well. If your garage outlet is a GFI, that can cause issues. Try plugging into a non-GFI plug. Also check the fuses in the panel, and most slide motors have a fuse in the wiring to the motor underneath as well. Do your lights work? If they do, sounds like an issue with the slide.
As for the crank, the owners manual might give you details, but on super slides, the handle is usually inserted on the opposite side of the trailer.
2005 F-150 FX4
2013 Rockwood Roo 23 IKSS