Difficulties in studying medicine
It may be a bit difficult to change careers to study medicine. You know, it takes a long time to study medicine at home or abroad, usually about seven years. You don't study medicine as an undergraduate, so you don't have much chance to study only in graduate school.
International English Language Testing System
Speaking of IELTS, what is your usual English level? I suggest you know the IELTS questions first. If you want to know how to prepare, you can sign up for an IELTS training class. Generally speaking, from not knowing IELTS at all to taking the exam, and it is necessary to do well in the exam. It will take at least three months. (And you have a good foundation in English) The IELTS test is quite difficult, so you must be prepared psychologically.
scholarship
As for scholarships, Australia is an immigrant country, so compared with the United States, there are few scholarships in those countries, especially if you have never been there before, which is almost impossible, but if you have done well in the past, you can apply.
Ielts score
As for the required IELTS score, studying medicine must be at least 7 points. Professional score of at least 85 points.