hanoi-avid-unite
Hi there,
You can find more information about the entry requirements on the link below, however, in summation, you need to complete an undergraduate and perform relatively well in the GAMSAT.
Regarding your subject selection, it comes down to personal preference. Since its a post graduate course, I don't believe that they will care very much about your ATAR. Instead, I would take a wide variety of subjects, to ensure that you are exposed to different fields. Personally, although the content isn't entirely related, I think that studying biology is good to get a taste of what medicine will be like.
I'm not really qualified to give life advice, however, don't force yourself to be a doctor. It's better to find something that you love, than to spend 6+ years of your life in medical school, be greatly in debt and hate yourself, just to earn an extra 0 on your paycheck.
https://study.unimelb.edu.au/find/courses/graduate/doctor-of-medicine/entry-requirements/#nav