My dream is to play in the AFL???

i am only 15, played junior footy for rockingham and warnbro, moved to a small town when i was 12 and have played against people younger and older than me... being 15 i cant play that anymore and i am working out and will play for the B grade team next year as i am only 169cm tall and are not playing for them this year(my dad lived in the city)?!!! please help!!!