There is a feature called "shiftlock". It prevents you from getting it out of gear unless you depress brake pedal. This requires brake light switch to be in proper working order. It also uses a switch down in the shifter. This switch can fail also. The solenoid that moves the linakge to allow gear lever movement can stick if massive amounts of sweetened liquids have been spilled on shifter in the past (your symptoms sound like the syrup plugged solenoid failure).

There is an override lever down just below the bristles in the shifter lever motion slot. You lift the lever while moving it out of park if it fails. This is an awkward two-handed deal, but if you can get it out of park when it won't otherwise budge, the use of this override will at least confirm that it is the shiftlock system that is at fault instead of some other problem.

P.S. The override pulling up like it's stuck in molasses also might be indicative of the spilled drink syndrome.