Hello! I was around that age when I joined PC, too! I was actually twelve years old but I turned thirteen some four months after joining, haha. I guess from our current ages though you are really young compared to me. But still, I know how it felt to be young, and to be on the doormat of a new forum at such an age. :D
But yeah, welcome to PC, Meiza! That is a pretty cool sounding name. :) Also, Sharpedo is awesome! All Water-types are, tbh. Your English is actually pretty good, so you don't have to apologize, haha. English isn't my native language too, but I coped with it soon enough and I think I've gotten the hang of it. :p Like Hikari said, this forum will do you wonders in the English speaking part, I guarantee it. You have to stay as active as possible though! You can only improve by practice, and not being around too much won't help you practice at all. That's what I did back then so I guess I still have a long way to go. u_u This forum shouldn't be all about learning to speak in English, though! You're supposed to kick back and relax here, not be in some sort of language school, haha. Fun is key.
Indonesia is a pretty cool place, by the way. I'd like to visit it some time. But before that, my welcoming reply must end first, haha. I wish you well on your PC journey! Enjoy your stay, Meiza. ;D