Definitely spend some time figuring out the diet, but still be a kid, plus at your age especially with added physical activity you'll need the calories. You can probably handle some fun food. Basically just cut the sh*t as much as you can and eat real food. Do not neglect your cardio. There's a lot of programs out there but I would stay away from any single body part splits (one body part per day). Whatever program you decide, include stuff like pull ups, dips, rows, squats, deadlifts, lunges, and other big compound movements. Google is also your best friend. I honestly don't do and have never done any specific program but hopefully more people will make some suggestions. Good luck and keep hanging around the forum. lots of good info.