Sound like the detent mechanism, should control first + second, is farked.
Otherwise there's an external rod, that's bushed on both ends, that maintains the proper distance between the shifter and trans. Inspect the rod, there's big silicone bushings on it. And check to see if there's any damage to the rod itself.
Might be bent but I'd think it'd be pretty hard to do.
I'm guessing, but if the motor mounts are worn, or incorrectly installed, that might cause similar problems.
To adjust the shifter the tower/stick has to be held in Nuetral, and the clamp on the shifter rod, under the car, adjusted to match the tranny nuetral.