2004 GMC Envoy "delco cd player wont work" Questions

delco radio light wont stay on i just got the car and swapped the radio because the old one wasn't working, so i installed it and sometimes the light will work but after like 5 minutes or less it will

cd inside and it whines pull in and pushes the disc i am trying to load out.. will i need to replace it with a factory player because its connected to everything or can i purchase an off brand and get

delco cd player in my 95 pontiac and when i put a cd in it ejects and says E20 Make sure you are using a original CD and not a copy. Some of the older CD players and some new also have problems with a