Welcome Ria!

Your Brownie likely uses either 620 roll film, or 127 which is a bit smaller. It should say somewhere on, or in the camera. Both sizes are available, but not necessarily easy to get. Some of the Australian members may be able to refer you to local sources.
If it takes 620, it's possible to use 120 size film which is fairly easily available. If you search "620" here there are many threads which discuss the methods of using 120 in a camera meant for 620.
Hopefully, using the camera won't turn into too much of an adventure, but there are lots of people here willing to help you through the maze.