Hi roiroi,
You maybe able to work as an AIN after completing 6 months full-time study as an EN in Queensland. You will need to check this though it may have changed since I did my EN's (I finished in 2014). I know a couple of friends that did after doing their first placement which was aged care. I would suggest that you get a casual job in hospitality. It is what you know and it would be easy for you to do (a no brainer) while studying without having to worry about learning a new job and studying. Hospitality may not be your thing now but it will pay the bills and allow you to live. I personally stayed in my retail assistant's job until I could get an EN job.
Best of Luck,
KKarmy