Traveling from Oregon to Sydney and Tasmania

I am wanting to plan a trip to Australia probably late November of this year. Possibly late February of 2027. I have some family in Tasmania but also want to explore Sydney. Before I book a $1000++ non refundable flight, is there anything I should consider before making these plans? Any travel hacks? Financially this is not going to be super easy for me to pull off but I really want to go. I’ve also never really traveled outside the US before so I need all the advice I can get. TYIA!