You are doing the right thing by "immersing" yourself in the industry...gliding..ATC (if you decide). Its all character building stuff too..which is brownie points in an interview situation.
What ever you decide to do study wise...A-levels, university or not...choose subjects you enjoy and will do the best in.
Gapan and Air League are great ways for young people to get flying experience. Gapan now offers ATPL sponsorships too occasionaly.
Best of luck