Weight loss plan for 15 pounds...?(Need help losing weight)?

Okay so, I've done a lot of searches on this and seen small things, like, giving up soda for a couple months and losing 15 pounds. Now, that's considerable weight loss for such a small thing, and bluntly I'm not sure small things like that would work for me. A lot of the weight loss plans online are designed for people with more..serious weight problems I guess. No offense, but, I'm not quite to that point yet and I need to find a better plan to lose weight but I can't find one anywhere!! I'm not technically overweight, because I checked and I'm at a healthy range for teens (I'm 14), so obviously I won't die or anything if I don't shed a few pounds, but I just want to feel better and be healthier? I'm about 5'5'', give or take an inch, and about 130-133 pounds. I've gotten pretty out of shape from doing charter school so xD Does anyone know what they would do to lose 15 pounds? I'm patient, I don't really need any specific time frame, but I'd prefer at least less than a year lol..? Thanks, and please don't be mean