Beau Jocque's first release, "My Name Is Beau Jocque" was what I learned on. Very simple tunes. Guess you need a Bb accordion, though...
Other than that, it may sound silly, but "Toot Toot" is a great first song to learn. I'll bet the melody is already "something you can hum", and that is the key to learning *any* song, brutha! -- Cajun, zydeco, rock & roll...