You should submit a ticket instead, you're way less likely to reach a Rioter on the forums. On another note you should give up your dreams now if you're not willing to do your own research or practice. Most people in your shoes already have full portfolios and sketchbooks

Hey I'm also 16 until next month and in a similar boat. A good start is to begin practicing the fundamentals, like anatomy and gesture. General basics at first. Industry standard art is real competitive and has high expectations, so the sooner you start and the more work you put in the better. There is also a ton of useful knowledge on youtube and the internet now, so you can get a long way without any kind of classes.