Seeking Some Advice for Immigration with My Girlfriend

So me (M 23) and my girlfriend (F 21) are attempting to navigate the tricky and wild world of Immigration to get together and start our lives off in the United States, of which I am a natural born citizen. As you all likely know, the world of Immigration and Immigration laws/ forms can be extremely tricky to navigate and understand without proper consultation - but I have no idea what kind of services I can trust or what we should be looking for.

Ideally, I want a service that will walk me through everything, step by step, and show me exactly what I need to do and review it all to ensure there are no mistakes. I also would really like to have it done by this time next year. We have been dating for 4 years, America to Australia, and have just completed our second face-to-face visit yesterday. Most likely the K-1 Fiancée option is the one we are looking to file.

There are services like Immigration Lawyers/ Attorneys, but I am unsure where to begin with them and if I can afford their fees. Attorneys can also be difficult to get a hold of, since the often only operate during the work hours of the week, and I can't take off days left and right to go meet with them. Then there are services like Boundless (claims to specialize in K-1 visas) and RapidVisa, faceless corporations that claim great success with the immigration process, but have just as many user reviews accusing them of being robotic or not invested with your case.

I want to make the right decision now, so that we do not have to waste countless time, money and energy on a service that will end up not giving a shit about us. Any and all advice would be welcomed.