Welcome! I don't know Auslan but there are a few people on here who do so good luck, maybe also try the sign language section and/ or do a search for auslan
I did checked out the website from WA Deaf societyWA Deaf - Home I noticed some of the links isn't working there.
Here is their contact details, perhaps you could call them to find out if there is Auslan Classes for you to learn Auslan.... I hope another West Australian AD member will see this post as well:
General Contact Details
Head Office
Street Address:
Suite 46 / 5 Aberdeen Street
East Perth WA 6004
Mail Address:
PO Box 8558
Perth BC 6849
Telephone:
From within Australia:
Voice: (08) 9441 2677
TTY: (08) 9441 2655