Hola Rodrigo, I am Mexican so I understand your feeling very well, let me tell you that I´ve been in aviation since 1995 and I´ve never experience something as good as real life ATC for the practice, back then this was just a dream.
If you keep listening A LOT of busy freqs for extended perdiods of time, Amigo you will educate your ears so well! in the other side, we all know that talking in the radio is much harder than listening so In my particular opinion go and buy the "COMM1 radio simulator" VFR & IFR, great help, is interactive and you´ll hear yourself and laugh about your communications in the biggining, but as far as you keep practicing you´ll be proud of your self.
Make friends in a controll tower theý are normally excellent people who will teach you alot if you are humble enough to accept it.(sometimes pilots think we know everything, but sorry, we don´t)
And at last, when I have a good time with my fellow pilots at home, we set the fire, the steaks, cold beers (not too much) and a loud speaker with a good congested ATC feed soundind back instead of music!!
Hope it is useful and have a great time down under!