Australia is one of the few countries where most banks will allow you to set up a bank account from overseas.
You can do this online on your chosen bank’s website, and it should only take about ten minutes. You’ll likely need a form of identification, like a passport, driver’s license, or proof of address (this is generally your Australian address, but some banks allow you to use your overseas address initially).
Once you arrive in Australia, you might need to visit a local branch of your bank to show your ID, allowing you to withdraw money and pick up your debit card.
Can’t open a bank account until after you arrive? Consider converting some of your money to AUD with an app like Wise or Revolut. This means you’ll be ready to go when you arrive in Australia, and you won’t have to carry large amounts of cash into the country.