We saw that you were looking at the Northern Beaches Community College near Sydney. Unfortunately, there isn’t a Croatian language course at this school. The only institution we are aware of that teaches Croatian is at Australian Croatian Community Services.
There is a Croatian language classes - Beginners course, Croatian language classes – Intermediate course, and Adult Croatian Language Classes. As this institution is based in Melbourne, you may want to go to the course page that interests you and full out the green Contact Form with an enquiry as to whether the class can be studied online or via correspondence.
Hope this helps!
Jesse, Compare Courses