Med School in Australia?

I am a grade 11 student in canada, recently moved here from new zealand- am nz passport holder btw- and i am looking to get into med school in australia after high school, now while i want to get into a med school in aussie i dont exactly know what it takes and am curious as to the standards of the high schools in australia ( such as averages, specific course requirements, etc). I also know that some or most of the medicine schools in australia are ready to take high school graduates into their med program, such as monash university and queensland university. Now i want to know if i will be able to get into these programs, and what it is i have to do to meet the requirements, i have looked at their websites, but i (preferably) want advice from someone who has attended a med school in australia and has first hand experience of what it takes to get into it. Also i want to know what kind of conversion system they use in australia to compare students of other countries, i do know that i need to sit the UMAT and plan to sit that as soon as i get to grade 12 ( also i want to know what sort of scores i need to get in the UMAT to have a good chance of getting in). Apart from that i have some additional information about myself, i will hopefully be getting a 93 average at the end of my first semester in grade 11 (results arent out yet), and i hope to continue getting as high an average as possible in all of my future subjects/courses. Also quite importantly, by the time i apply for a position to a university i will have had volunteer experience at a hospital ( i have been told that these kind of these things are good to put in ur resume/letter of intent when applying) and that ia about it. Pls help me out here, as i am kinda clueless and i want to know what i still need to achieve in order to comfortably (hopefully) acquire a position in a med school in australia.