If you were over 25 or hold a drivers license in another country it is much easier to get permission to drive in Australia. Short term visitors (up to 3 months) can use an International Drivers License.
Longer term need to sit the test to get an Australian licence.
As you are under 25 & don't hold a license. You will be required drive under the supervision & instruction of a fully licensed driver for at least 120 hours. You need to keep a log book as evidence of this.
This time can be reduced to a minimum of 100 hours, if you are taught by a professional driving instructor (PDI). As each hour of professional instruction counts as 3 hours. Up to a maximum of 10 hours. Then Professional Instructor hours count the same as any other licensed driver.
Professional Instruction costs ~$60 - 90 per hour.
Typically asking someone to give up 100+ hours of their time to teach you to drive is a big ask. Especially as they need to be on their full license. Not provisional as most 18-19 yr olds are.
So if you lack the friends with the car you, should budget ~$7,000 to get your license. Driving Companies will typically give you a discount when you bulk-buy hours. (10 or more)