96 Buick LeSabre 3.8L Possessed Shifter

I have a 96 Buick LeSabre 3.8L with a possessed shifter. I watched the YouTube videos on the $2 bushing but I cannot find the spot that the bushing would go into and the parts stores say they do not have it. The dilemma is this: I turn on the car, shift into forward or reverse and nothing happens. I jiggle the shifter no correction. I shift several times back and forth and nothing happens. I shift back and forth some more and just maybe like winning the lotto the car goes into gear. It drives normally until I turn it off…then the mystery begins…will it start…will it shift into gear??? Do you have any ideas as to what I could look for? Thank you as always…you guys are great!!!

You’re describing a slipping transmission when it’s cold.

Have you checked the transmission fluid level. color, and odor?