Bro, I'm telling you now....cut out the soda pop, fruit drinks and anything else you drink that has sugar/carbs in it. Just drink water. you wouldn't believe how many calories and excess crap those things add in your diet. Of course you should exercise as well. If you make sandwiches use only whole weat bread and use the diabetic deli meats- they have little to no sugar/salt/crap added. try not to eat any carbs after 7pm. follow this and you should lose weight. Do it now because when you get older it gets much harder to lose. Plus, hot chicks don't like fat kids. trust me, I KNOW.
Good luck