Ok, that's really not my style of music but if I recall, Greenday did a great accoustic piece with only guitar and vocals.

Time of your life

Here's the link.

http://www.greenday.net/tabs/tabs_timeofyourlife.txt

If you don't feel ready to pick the notes just strum them it's going to as good anyway.

I really don't know a lot of punk so I may not be able to help you much more than that sorry.

This the link to almost all greenday songs.

http://www.greenday.net/tabs.html