Too late for tomatoes - Melbourne cup day is tomato planting day.

Beaware that some vegies and herbs don't like their roots being touched or anything once they start - beetroot, coriander and a few others. Best to plant the seeds where you intend to grow them, or plant them in those tubestock pots so you don't disrupt the roots when you move them.

Mint likes wet and can handle shade. It can be a bit of a weed - so some people recommend planting it in a pot on it's own so that it doesn't take over. Parsley is awesome and shoudl grow well ATM.

Year round Lettuce is a great crop - i think it would like the idea of starting out in a green house, but i've never tried.
My capsicum is going OK, but I'm not sure if you are too late with that? Watermelon - how big is your garden ? I think watermelon spreads a lot.

I find zucchinis are easy to grow and also easy to put in a lot of meals. But that season is over too now. Beans and peas time, I think? Have you though about planting spinach? It's easy too.

Maybe google Gardening Australia - they know more than you can ever grow!!