I am trying to find out what it takes to immigrate and become a citizen to live with my girlfriend. We are not trying to anytime soon. I just need to understand the process. I'm very uneducated on how the laws in Australia work regarding immigration and unfortunately we can't exactly get a partner visa since we are not married. We're both young but I am not looking for anyone to try and discourage me from looking into this for whatever reason. I would just like a civil, pollite explination about how to permanently immigrate and live with my girlfriend.

How long can someone visit the country and stay with someone at their house, how long until they no longer qualify as "on vacation" and require at least a visa of some kind, how do I optain any sort of visa, work or otherwise, that allows me to stay, and how do I become a citizen?

I currently live in USA and I am unhappy here. As I said, I want this to be permanent. So please if anybody knows how to go about this situation, please let me know. It's good to understand this for the future. This won't be anytime soon, as I am getting a place with some roomates very soon (for probably a couple years) but as soon as I can financially afford to immigrate, I plan to.