What songs are good to sing and play for guitar for friends who are going to college?

I am a high school senior graduating in two weeks and i really want to sing a song for all my friends as we go our separate ways. I am a baritone singer with a range from middle tenor to low bass and i can play the guitar fairly well, but i cant seem to find any good songs, so i was wondering if people on here could give me some good advice on songs?