Acting Positions/ websites for 13+ year old child in Northern Ireland?

-Hi, i live in northern ireland im 13 years old, ive have always wanted to be an actor so do any of you guys know either good sites (preferbly ones i dont have to sign up to) or actual places where i can find acting position. also would people in school make fun of me or anything like that? i go to a school called Wellington College Belfast and was wondering if any of you guys that reply go to the same school know if there is acting classes/ support,

thanks.