I'm also from the midwest (Cincinnati) and also began playing lacrosse with a fledling high school program. First of all, which position to you plan to play?
If you want to be a middie, then you need to prioritize a running program. The general guideline is that you should be able to maintain consecutive 6 minute miles. You should also do sprint work and agility drill. I highly recommend checking out the site: www.posetech.com to learn the pose method of running.
Attackmen and Defensemen play slightly less cardiovascularly intensive positions. If you plan to play either of those, then you should focus more on sprint work with some long distance work on the side.
In the weightroom your focus should be in this order 1. forearm strength (wrist roller is the traditional lacrosse workout tool) 2. abs 3. shoulders 4. triceps 5. lower back and hamstrings 6. upper back 7. biceps 8. calves. I would say that any program specializing in football or basketball prep would work well (settled offense and defense in lacrosse resembles basketball).
Finally, get a stick and a ball and start throwing against a wall. Go to www.laxworld.com and invest in some instructional videos/dvds.
I’ve known a lot of very good lacrosse players both from high school and especially college. There are tremendously successful players of all sizes. However, they all have three things in common: great knowledge of the game, great stick skills with both hands, and great speed.
Best of luck, lacrosse is a great game.