That's a great goal and It's definitely possible. I'm 16 as well and I basically did the same thing but I probably started off in much worse shape seeing as I didn't even have anything resembling a 4 pack at the time. You at least know your facts, If you want to get a six pack you're definitely going to need to get your body fat percentage down seeing as fat accumulates on the lower abs quite easily. A low body fat percentage comes from a combination of a good, lean diet and exercise. For your diet I would stick with mostly complex carbs and proteins while fats constituting the lowest percentage of your diet. There are a few things that you need to keep in mind while losing weight and toning muscle. The key to losing weight is consistently attaining a calorie deficit on a day to day basis. Because of this fact, it's good to avoid high levels of fat because they have almost twice the calorie density as carbs and protein do (fat= 9 k/cal per gram, carbs/protein= 4 k/cal per gram.) While weight lifting do core exercises every time you work out while rotating the exercises you do with the rest of your body so you don't injure yourself. A good start would be rotating from upper to lower body exercises. In addition to weight lifting its important to do aerobic exercises. This means running or biking a lot. I would start off running as far as you can go and slowly working up from there rotating long days with short days so as to avoid injury.
