Well, unless he's flying a plane that requires >1 crewmember and you are appropriately licensed, you'll be a passenger not a co-pilot. Also I'd consider very carefully before flying with someone who just got their license. Checkout this book if you want the real story:-
http://www.amazon.com/Killing-Zone-H.../dp/007136269X

Also please don't use the radio unless you really know how to communicate and respond to the real world of flying. Ch9 is not preparation.

It's great that you are interested in flying, it is a great passion, but as the saying goes "Aviation in itself is not inherently dangerous. But to an even greater degree than the sea, it is terribly unforgiving of any carelessness, incapacity or neglect"