Here's some simple free advice.
Don't buy anything until you've been to a game. Wait until your 18, attend a local game (there are tonnes in to) and rent. You will gain a first hand understanding of the sport and the dynamics of it, this will also give you the chance to meet players and talk in person with them as well as see what kit is used and how.
First hand experience is key. Also, with airsoft start off with a bone stock AEG from a reputable company, use that gun to build your soft skills and understanding.
Cheers and welcome.