Yet another Aussie chiming in. (Aussie is fine, its what we call ourselves.)
I’m in Adelaide, which is, interestingly, a sister city of Austin.
I’ll reiterate a couple of points from above.
Distances are huge. Sure, we are about the size of the continental US, but there are very large stretches of absolutely nothing. Like the US, a one way east-west coast trip burns an entire day. City to city on the East coast can burn half a day when you add in airport overheads. Getting to northern Queensland can burn a day. Travel by car is not going to be an option unless you are here for much longer.
And really, two weeks just is only going to be enough time for a limited number of things, especially if you are including international travel in that time. Do try for longer.
Oz is a pretty easy cosmopolitan western nation. Anyone from the US will feel totally at ease. If you want something different to home, you might want to get out of the cities.
You can find nearly every cuisine available on the planet here. And it is very good. Mexican is however universally awful. I don’t really know why. Italian is really good. We have a huge immigrant Italian community that has been here for generations. Most other European cuisines are well represented as well. Although you might not consider yourselves food adventurers, I would really suggest making the effort to get to find some of the other good food on offer. And our wines.
Music. We don’t have a Sixth Street. Heck, nobody else does either. That’s why we all want to visit Austin. Post covid it isn’t clear what the live music scene will be. But what Oz gave the world musically was pub rock*. Sadly that was a different age. There are music and arts festivals around the country, and they can be very good. You might consider a visit to coincide with one. Depends a great deal on what you really enjoy. (We have both kinds of music here.) There are music enthusiast societies for most music, you could do worse than to chase down a jazz or blues society (or whatever) and see what they are doing and where they hang out.
But what is the Oz experience? Reef, Harbour, Rock has been the standard for many. But it doesn’t need to be. Despite the warning about distances, taking a serious road trip as part of a visit is a great way to gain a feel for the place. Here the journey is the reward.
I’ll give the example of where I am, in South Australia. SA isn’t exactly first on most tourist’s list, but it is what I’m more familiar with. It gives examples options. Other states have very different things on offer. We have - the Flinders Ranges. Places like Wilpena Pound or Arkaroola get you into the outback. Don’t visit in our summer however. Kangaroo Island. A little potted sample of flora fauna and history. Much wiped out in bushfires, so don’t bother for a few years yet. Winery districts. Lots of places to stay, mooch about, try the wine food etc. We are all very low key here. The Eastern States arguably have wider range of things, but it depends on what you enjoy.
Colonial history abounds, and is similar to the US in broad brush terms. Life could be utterly brutally hard. It is a harsh country. History of the indigenous peoples is harder to find. We arguably have one of the worst histories on the planet in how that went.
There is much to think about.
*Pub rock was a do or die baptism of fire. Faced with a bar filled with drunks wanting to be entertained, you got good fast, or you got out. They were fabulous days.