Hello,
Breast reduction surgery has many side effects and as such wouldn't prefer you going for it as you are just 16.
When a breast reduction is done most part of the glands and ducts are removed. This will interfere in lactation in future as ducts are removed. Apart from that, you need to understand it's a normal part of anatomy of a woman. It's unnatural to reduce the size, in surgical ways. Apart from just reduction of glands, it can also effect in you other ways like cosmetically as well, scars will be left etc.
I suggest you take counseling for now, as you need to appreciate your natural body and anatomy. You can try exercises like pushups and dumbbell exercises; these will maybe reduce the fat in chest and build your pectorals' muscle to an extent. If you are still persistent about getting surgery done, you can consult a surgeon.
Thank you.