James Sheppard

Hi I have a 2009 e300 I had the car sitting for a couple months due to the weather I had the radio on last week and it was working fine so I tried to start the car and of course wouldn't start so I had to boost it now when I try to put the radio on no sound will come out I put a cd in and it plays I try to put the am/fm in and it says please wait then it says unavailable can some please give me a hand