Cut down on your Sugar, Starchy, and Fatty foods for a start. Replace all your Soda drinking with plain old H2O. Make a routine of exercising 30+ minutes a day. To give you an idea, anything that gets your heart pumping and causes you to break a sweat is a good exercise.
Push-ups, Sit-ups, and light Weight Lifting is a good start for toning. Do 3 sets of each exercise throughout the day. If you dont have a dumbbell or anything, Push-ups will make up for it.
Make an eating plan similar to: Breakfast, Snack, Lunch, Snack, Dinner. Eat healthy things with Protein. Peanut Butter, Skinless Chicken, Whole Weat Bread, Tuna (any type of Fish for that matter) or even a Salad. If you are on the run and in a hurry, a quick stop by Subway for a (healthy!) Sandwich is an excellent choice. I even go to Subway all the damn time! Space your snacks and meals accordingly throughout the day as well. 2-3 hours apart is normal.
When is prom? Because I would suggest that you start an exercise routine right this very minute. I would expect, if you follow your eating, and exercising routine, around 2 weeks to a month to see results in your body. The longer you wait, the longer it will take to see results.
Good luck with everything.
