15 year old actress looking for auditions

Hello. I am a 15 year old aspiring actor. Tomorrow I will be auditioning for a theatre production. I need to gain some experience before I can start auditioning for TV shows and movie films. I live near Melbourne, Victoria. I was wondering, is there any new casting for TV commercials, short films, small roles in TV shows that I could audition for? Any suggestions would be accepted and great! :)