You can get more information about them and their campaigns on their website, which is http://www.getup.org.au/. From there you will see whether it suits you and whether you'd also like to sign up for their emails and maybe participate in their program of action.
Some of the campaigns that they are interested in:
- easier access to enrolment for voting
- climate change
- native forests
- internet censorship
- paid maternity leave
- mental illness, etc