Why not track? That's what I would do. Lacrosse is fun, I've played it a little bit before... and so is soccer. Out of those two, I would chose soccer.
lacrosse sounds good! dont try soccer- its way too competative for someone who hasnt played...lets see.. pretty much all of their lives?! haha. but tennis is good too! sounds girly, but its easy to get good at & its good exercise. cross countrys always good too!!