positioning yourself for research positions after graduating from a PhD in a different country
The most important thing you can do in your first year is to master the material and do well in your courses. 

Present your research at conferences in Australia (assuming your program has some funding available for this). This is a more effective way to meet people in your field than sending emails to busy faculty who know nothing about you or your abilities as a researcher. 

I don't know how long your PhD program is, but you have time, and presenting repeatedly at Australian conferences would be an excellent way to develop professional connections. You will encounter the same people multiple times at these events over the years. I have even developed lifelong professional friendships with colleagues I first met on the conference circuit.