Since your a novice I'd say any of the made easy versions of songs on here would be a good start. To make it interesting with your musical partner you could play the open chords as tabbed out and he or she could play same chords but in different voicings or even in different keys via a capo. Might come up with some interesting sounds there.

Another option could be one of you play the chords and the other play along with single note melody.

Have fun,

Moe