The Aussie Environment and Australia communities are probably the best placed to get started on koalas. I wouldn’t suggest making a new community yet until you need to, there are a lot of unused ones due to the lack of users. Koalas suit the theme of !environment@aussie.zone (how do I know? I posted all the posts there).
Looks like Aussie.Zone has the most mentions of koalas.
https://www.search-lemmy.com/results?query=Koala&page=1&mode=communities
The Aussie Environment and Australia communities are probably the best placed to get started on koalas. I wouldn’t suggest making a new community yet until you need to, there are a lot of unused ones due to the lack of users. Koalas suit the theme of !environment@aussie.zone (how do I know? I posted all the posts there).