'90 Integra stereo issues

Hey guys I wonder if anyone out there can help me. I just picked up a 1990 Integra LS with a cassette player and I dont really have the money right now for a deck because I have another car I throw my money into so I wanted to hook up my portable cd player with the cassette connection and all. When I did this the tape goes in flips sides about 3 times and spits the tape back out, fast forwarding doesnt do anything and I have tried other tapes, it does the same thing.. any ideas? the "Clean" light is not coming on and if I need to clean it what is the best way to do it?

thanks :D