I think cascade style might be a challenge with natives because most are very strong upright growing. You could try prostrate varieties - acacia, kunzea and there are now prostrate callistemon and leptospermums that might be ok. The classic cascade native is Dorothy and Vita Koreshoff's Rulingia hermanifolia but I have found it hard to keep looking good in the long term.
Other native species that are making good bonsai include: Ficus, Callistemon, Melaleuca, Banksia, Leptospermum and Baeckea (now known as Sannantha). There are some very nice Acacias as bonsai but I have not done very well with them so far. there are lots of other species that people are growing but some are quite difficult to keep looking good.
Cultural tips for Banksia, Callistemon and Lily pilly: Root prune and re-pot in warmer weather (November - Feb). Standard potting mix. water as for any other bonsai. Feed as for other bonsai (note that banksia can be sensitive to P. Best to use a low P 'native' fertiliser until you have learnt a little more. Callistemon and Lily pilly love normal fert) Most natives are active over winter so keep fertilising, even through cooler months. All 3 of these can be wired safely at any time of year. Prune whenever you feel the need but, like most other plants they won't grow back very fast in winter. Most natives prefer plenty of sun but you will need to balance sun with your ability to water. Best to start with some afternoon shade so they don't dry out too much on hot afternoons. Lily pilly is a rainforest species so will do better with a little more shade.
Lily pilly can be sensitive to cold temps but the others are hardy and will not need protection.
Look for inspiration in the photos from the Australian natives as bonsai exhibitions in Canberra
httpss://www.anbg.gov.au/bonsai/ or go to Canberra Bonsai society pages.
You might also find some help at the Victorian native bonsai club
https://www.vicnativebonsai.com.au/ they have just held the second native bonsai show in Melbourne. Pictures of the trees on show have been posted on Ausbonsai
viewtopic.php?f=25&t=21502
You should also find lots of other threads, including which species are suitable and culture tips here on Ausbonsai if you use the search button.