I don't understand studying medicine?

In the UK, medicine is an undergraduate course; so you go straight into medical school, rather than doing an undergraduate degree first.

Medicine in the UK is massively competitive, and you'll need outstanding grades to even be considered. As an Australian resident (irrelevant of citizenship) you'll be considered an international student, so would be charged higher fees ,and be ineligible for student grants and loans in the UK. Have you considered how you're going to fund this?

Studying in the UK, even with medicine, does NOT lead to residency or a visa; so plan on returning to Australia on graduation.

As for the rest of the EU; what languages are you fluent in? Medicine is almost always taught in the language of the country; so if you only speak English, your only option is the English-speaking countries (ie the UK, Ireland & Malta)

Few countries have any real shortage of doctors these days, and applications for hospital residency/post-degree practical training in medicine is nearly impossible to obtain outside your country of citizenship. If you are Australian, you're going to do your residency & practice in Australia, so you'd better go to school there.

UK has undergraduate medical degrees rather than MD, but it still takes about the same amount of time as Australia's bachelor's + MD. Problem is, you have to go home, take Australia's qualifying exams, then look for internship/residency as a foreign medical graduate. You will NOT remain in UK (or anywhere in Europe) to practice. You have to return to your country of citizenship immediately upon completion or termination of studies.

IF you really want to be a doctor, and you are Australian citizen, you really need to do bachelor's degree (perhaps you could do this abroad, or a "junior year abroad" program as an undergrad?), then earn your MD in Australia.