No power key stuck in the ignition
Changed mega fuse still no power
you must have a fresh 12.5 volts at 30 amps to turn the startermotor, one problem is the battery sweats corrosive material, best if hosed clean periodically, wirebrush to remove the corrosion periodically, as far as the key being stuck, they would NOT like a lawsuit with the key popping out and functions ceasing, once you have a proper battery with solid connections, then use the "shut down procedures" foot on brake, selector in Park door closed and possibly turn left turn right to allow the key to be removed~ wheels sometimes offer torsional resistance, preventing removal of the key~
Battery connections that are not good and tight will cause this. Also, check the ground on the transmission hump on passenger side. Close to Gear selector, 1 screw, pull carpet back, it's right there.