[Broke College Kid]

I recently inherited a 91 Caprice Classic from my great grandfather. The car is in pretty good shape. It has 101k miles, and few dints and dings but no rust. The car is equipped with a keyless entry system which no longer works. I’ve changed the battery in the transmitter with no luck. Could it be the receiver? Where is the receiver? Is it the thing in the blue thing in the defrost vent? Another problem the car has is with the radio. When it is turned on it makes an ear piercing high pitched screech no matter if it is on am or fm, every station and with a tape in. What could be the problem? The driver’s side window is also off the track, how could I fix that? I’m at a loss. Could I fix any of these problems myself? Any help or repair suggestions would GREATLY be appreciated

Cody