In britian i hear they walk around and say something is "Leet", while here in america we walk around saying "Man that was so one three three seven". I think that's the biggest diffrence i've seen.

(you're 14, i was 15, it's not that big of a deal).

I don't really believe it's easier to learn languages at a younger age
I know a brother and sister, moved here from Rostov 3 years ago. The Guy is 18, his sister is 15. The guy, can speak conversationaly perfect english, but he has an accent and sometimes fumbles. yet, his sister who is now 15, (moved here when she was 12) who i never talked to untill today, speaks perfectly perfect accentless normal english.

I think that age can play a diffrence... Once you get to a certain point, the muscles in your mouth (along with your brain) can't / wont want to work to creat difrent sounds, and your brain has a harder time accepting the info.

I know that difrent people have diffrent skills, they both seemed to learn english just fine, but i think it's pretty obvious age had something to do with it here.