the transmition dosent shift smooth what could be the problem

That car likely has the old C-4 transmission under it. I don't think the AOD was available in 81. If I am right, I would bet someone put Mercon transmission fluid into it. It SHOULD be Type F. The two are not interchangeable. The first thing to do, if it is an old C-4 is to have the filter changed and a power flush done to remover as much of the old fluid as you can. Then make sure the kick down rod is adjusted properly. These transmissions often outlive the car, so it is unlikely to be anything major.

it has 95000 miles on it and it changes gears to late I think it don't change to second until about 30 miles an hour so driving around town its not often it comes out of first

1980 Continentials/Towncars had AODs. Ive heard before that the throttle valve bushing on the AODs go bad after a while?

The first thing to check is to make sure the kick down rod is connected at both ends and is adjusted properly. There is an adjustment at the bottom to ensure clearance between the rod, the body of the car and the engine, and there is the one at the top to adjust how aggressively the transmission kicks down. If there has been something done under the car, it is possible the rod has come disconnected from the linkage. If everything is intact, it should just push right back on the stud.

I have a feeling the 81 had the VV carburetor, in which case it is a kick down rod. If it is fuel injected, it is a kick down cable. The cables can come off their mount if the grommet deteriorates. Also, the cables can stretch. Either way, it will cause transmission failure if left. It is also the most common issue with these mechanical transission.