i am an australian, wanting to know what I need to do to be able to get married in china.

You can enter China with a tourist visa for this purpose.
The required documents that you should prepare in advance for marriage registration in China are as follows:
1. Single Status Certificate attested by department of foreign affairs and trade, and then get it notarised by Chinese embassy or consulate which holds the consular jurisdiction of your area.
2. Your Birth Certificate. Be note that all originals should be translated into Chinese before notarised by Chinese embassy/consulate.
Other details, you can refer to https://www.travelchinaguide.com/embassy/visa/marriage-registration.htm