If you want to work as a professional model in Australia, you should consider joining a reputable agency. This is because being a model requires the right training and the only way you can get the training you need is to attend the right school.
A reputable agency will teach all you need to know about the business side of modelling. To succeed as a model, you need to learn how to create and use your portfolio. You also need lessons on walking, speaking and presentation.
As a model, you need skills in customer relations, contract negotiation, basic accounting and record keeping. The right school will teach you all these things and more.
As you can see, you cannot train yourself to be a successful model. You need an Australian model agency to give you the training you need. Find the right agency and you are on your way to success.