Professional organisations can be an incredibly useful resource. You should join the relevant ones as soon as possible to become a part of your professional network. They provide professional learning, advocacy, opportunities to attend conferences, and professional teaching journals. Many of these organisations also offer a discounted student/teacher membership rate. 
It is advisable for you to join your state/territory body first, as they will likely have the most relevance to you. You can also follow their social media accounts to stay up to date about what's happening in your state/territory, as well as throughout the country.

For all languages - national

The Australian Federation of Modern Language Teacher Associations (AFMLTA) is the national professional body representing teachers of all languages in Australia. It publishes the Babel Journal, and hosts a biennial national conference for teachers of Languages.

The Film in Language Teaching Association (FILTA) "is an association of language teachers, film educators and researchers." While it is a network based in the UK, it is it possible to connect all over the world. Study guides for popular films in several languages are available here as well.

"AFMLTA has developed a suite of Professional Standards resources to support Languages teachers in reflection on practice and planning for future growth."

For all languages - states & territories

Single language teacher associations in

states & territories

Details for these associations are usually available via the state/territory teacher associations: Victoria | NSW | Queensland | WA | SA

Community languages

The Community Languages Australia organisation represents community and ethnic language schools in Australia. It is also represented at a state/territory level. These local organisations include the Ethnic School Association of Victoria and NSW equivalent.

Language & culture organisations

Apart from keeping your own language skills up to date, language and culture organisations offer libraries and resource centres, special cultural and school events (e.g. essay and poetry competitions or film festivals), exhibitions and other useful opportunities.

Also remember that often the consulates or embassies of the countries where the language you teach is spoken might organise cultural events that are suitable for schools as well.

CHINESE Confucius Institute  |  FRENCH Alliance Française in your city |  GERMAN Goethe-Institut Australien  |  JAPANESE Japan Foundation |  INDONESIAN Australia Indonesian Institute  | ITALIAN Dante Aligheri Society; Istituto Italiano di CulturaSPANISH Instituto Cervantes