1992 Lincoln Town Car Will Only Shift Into Drive. Gear Shift Loose Will Not Go Into Park Or Reverse Just Drive?

Ford Motor Co. Of your cars vintage, used plastic bushings to attach the shifter linkage from your shifter all the way to the transmission.
It would be my guess that one or more of them are simply worn out.
If I am right, it is a cheap fix. The bushings are cheap even if you buy them from a dealer.
If you aren't sure what to look for, have an experienced mechanic check it out.

At the end of your shift tube' which runs on the top of your steering column' there are two screws which hold the plate that attaches to your linkage. If these are at all loose it will make the shift lever feel loose and sloppy and not allow your linkage to reach the reverse and park position. The connection is above and a little in front of the break peddle, a pain to get to but a lot cheaper than going to a mechanic

Sounds like your shifter cable