Re the check engine light...You really gotta take it to a pro and see what codes come up on the analyzer. You cant possibly get an answer here. You can try disconnecting the battery for a few minutes and see whatt happens when you reconnect it.
Re the radio....it could very well be a fuse.
Check your fuses, or have a friend do it if you aren't comfortable with it.
I'm not much of an electrician. Maybe someone else can chime in to verify or debunk what I'm telling you.