First off, welcome to iRV2!
Second, you should add a "signature" to your profile. It contains whatever info you want; most people put info about their coach there, so they don't have to type it into each message. Instructions for adding a signature are here
As for the radio, chances are high your coach has a 1.5 DIN Magnadyne M9900CDS (manual is here
). A prior owner could have replaced the original radio. Post a picture here and we could offer better advice. Instructions for posting a picture are here