Should I do kickboxing?

I want to lose weight. I'm 14 year old girl and I weigh around 130lbs. I want to lose at least 20lbs. I play fieldhockey, and track-field.& I'm not fat, but I want to try a 3rd sport and I think I would be really good at kickboxing, because I'm really agressive. Any tips/ ideas on like how to start or expierence or anything?