"You're eligible for free roadside assistance if you're 16 - 20 years old, you're able to join the NRMA for free if you choose Free2go. However, this will only cover you for 4 callouts per year."
If you're between 16-20 years old, when you enter your date of birth on the sign up screen, you will be given an alert for the promotion. Covers 4 callouts per year, and I'm sure further fees will apply for repairs, etc.
Only for the first 2 years.
Get the first two years free
When you join at 16, or first year free for drivers 17 to 20
https://www.mynrma.com.au/roadside-assistance/free2go