Sydney Seed Starting Dates / Techniques

Hi All!

I’m based in Western Sydney, and planning a garden upgrade that includes 4 raised beds for vegetables.
We have dabbled in veges in the past, but always direct sown seeds or bought nursery seedlings.
Just with the amount of growing space we have this year, I’m interested in starting my own seedlings and getting some healthier transplants.
How are people in our climate doing this? Do I need to have the whole warming mat and growlight setup? Can I use an outdoor pop-up greenhouse? What dates do Sydney gardeners generally get things started for spring transplanting?

Thanks!