What's a good thing to do with your friends during the summer
You could go biking with a group of friend or camping. If you have beaches close to you that would be the best place to go and play some football. You could also go road tripping if you are legal. Have a look at this for ideas http://parentingteens.about.com/od/teenculture/a/funteenstodo.htm.
Hangout or go to the pool