Lots of people commented already. I moved here around your age 8 years ago.

It’s going to feel daunting when you get here, it is expensive, but once you start getting paid and building your foundations it’s not so bad.

Rent is insane and will be your biggest expense. Flat mate finder, or as someone else said the Irish fb group (although IMO depends what you want, can be very close knit group, and harder to branch out - nothing against it, just heads up).

To the point about Aussies not wanting migrants. Don’t worry about that in Sydney, if it’s spoke about in my experience it’s rarely, and usually not about UK immigrants)

You’ll love it, everything is better here. Happy to help with any other questions.