So my girlfriend hasn't heard me play the guitar yet, not because I'm embarrassed or can't play, but I can't find a good acoustic song to play. All acoustic songs I play are just chords over and over (and I can't sing) so I need a beginner to intermediate instrumental song to play on acoustic guitar. Help is much appreciated.

God Bless.
Learn to sing. Girls would MUCH rather have you strum boring chords and sing than play some technically difficult instrumental song. After you sing her a song, THEN it's ok to show her some cool guitar songs. As for recommendations for good acoustic only songs, you can't go wrong with zep. check out some zeppelin three
by the time you read this you will be wasting your time because it doesnt say anything