Yes, you need to apply for a tourist visa to China through Chinese embassy or consulate according where you reside. If you work for a long time in Sydney, you can apply from Chinese Visa Application Service Center there. Your passport is Ok for use since it is valid for more than half a year when you submit your application to the embassy in April or March.
Other documents you need is as follows:
1. The application form of People's Republic of China;
2. One recent passport sized color photo;
3. Travel itinerary prepared by travel agency, copy of return ticket (e-ticket);
4. invitation letter from relatives or friends in China including the inviters' personal details and contact information (if any).