How to lose weight and gain endurance by febuary? -

im 17. about 5 5 and 138 pounds. i was in excellent shape in the summer because i ran almost everyday but unfortunately i havent run at all in months. i want to lose at least ten pounds; mainly in my stomach, and gain endurance by febuary for a vacation and lacrosse tryouts. im joining a gym but really have no idea what to do there. any ideas?

Try the lil jack workout http://www.youtube.com/watch?v=TKCGe2Ezr��Merry Christmas http://www.youtube.com/watch?v=N388Jwxao��

try interval training