the amount you can safely lose is 1 percent of your body weight per week... so in 12 weeks, you could lose about 36 pounds which is a good start towards your goal...
Eating 2 meals a day is not good for you because you want to keep your metabolism revving along... and only feeding yourself twice won't let that happen. Its suggested a person eat 5-6 small meals per day rather than larger meals.
Giving up soda is good for you, soda gives younothign but sugar and empty calories... and working out is good foryou, though 2 hours x a week shoudl really be brolen out into 30 - 45 minutes every other day...
GIven your age, talk to your parents about your goals and perhaps your family physicial to give you some more ideas about reaching your goal.. Your body is still developing at your age, you want to lose weight as safely as possible.
Good luck