New to camping - gear? (Australia)

I am completely new to camping, but have young kids and would love to start my collection of camping gear (Facebook Marketplace for good quality 2nd hand) in preparation for the coming years to the family camping. What equipment/gear has worked for you, and that you'd recommend to a camping newbie? What can you cheap out on and what would you splurge on?

My location is Brisbane (Queensland, Australia). TIA!