I'm 15 and losing weight too!! I've tried and failed so many diets, and this is what has worked:
-eat slowly, chew thoroughly, and take breaks between bites. Set down your fork and sip some water. All these tricks will make you feel fuller.
-drink LOTS of water; your first few pounds will all be "water weight" so it's a great way to start! Water keeps you full, hydrated, and healthy. Great for your skin too.
-pay attention to how full you feel. When I was hungry, I used to make huge "snacks" that were more like meals and just wolf down the whole thing without stopping for air. Instead, tune in every few seconds and think about how satisfied you are. Starting to feel full? Leave the food, do something else, drink some water. It's okay to leave food on your plate. (And if you're hungry for something later, you can always finish it!)
-stop eating after a set time at night; I like to do 8 PM. Your body struggles to digest food whilst you're sleeping, and besides late-night snacking can be the worst snacking. People have lost up to 20 pounds by making this change alone. Going to bed hungry can be hard, but you'll wake up feeling so much better.
-if you're hungry, there are some great low-calorie option "quick fixes": fruits, vegetables, soups (not the creamy ones! vegetable soups), warm tea.
-you don't have to completely eliminate everything. If you have a weakness for Ritz crackers, allow yourself to (slowly!) eat a few every day.
-this may sound weird, but when I'm trying to avoid being tempted by a food, I make a gesture with my hands (kind of a "no!" gesture). For whatever reason, this physical action always works for me.
I hope this helps and GOOD LUCK!!
Lost 12 pounds, 12 more to go :)