...are you posting from a smurf? 'cause, best as I can tell, this account is lvl 36, and is in S2, not D3. If so, post from your main account, so people can actually see what you're doing, and give you specific advice.
More generally, there's millions of League players. There's hundreds of LCS players. Your odds are poor. To truly get into the LCS it means treating League like a job. It means reading the patch notes as they come out. Staying right on top the meta. More importantly, understanding the why of the meta. And it means playing, playing, and more playing, to understand the champions, their ranges, their mutual interactions, and much more.
Even more important, you must be a team player. Understand team comps, and know how to adapt yourself to them. Know when to play a tank, when to play a supportive role, when to go AD or AP to complement your draft. Yes, your mechanical skills are important, but fitting in a team is even more so.
Finally, at 16 y/o: Stay in school, do your best. A career in league is a long shot at best. If you have the skills to make it big in this, you have the skills to do so in a more conventional career too. Keep you options open.