1994 525i

Hello. New to this group
I recently bought my new/old BMW from a friend of mine.
My question is:
The dashboard computer kept signaling one of the taillights was out.
I replaced all bulbs on that side.
That side worked, but the next day, the other side went out.
Replaced those bulbs.
Same thing with the OTHER side I had just replaced....
To be sure, I checked the fuse box, and everything was in working order.
Also, the passenger window is acting strangely.
When I first bought the car, it did not work. About 1 month later, it
started working, then it stopped again lol.
There was no fuse for it Just had to make sure.
When you press the button, you can hear *something* happening, but no
movement. Would this be something akin to "off the track"? Do you think,
after obtaining the proper manual, it would be something I could fix?
OK last one, I swear! The driver's seat will move, but once it gets to a
certain degree forward, only one side moves and the other side stays still.
I have to sit a bit crooked
Since the motor still works, any ideas?
We were thinking of replacing the motor with one from a junkyard....
(If you cannot tell, I do most of my own repairs. I just have never had a
BMW before lol)
Thanking ya'll in advance,
Rainey