What permits/ licences do I need?

This will very much depend on the type of business you intend to start. The advantage of buying an existing business is that all necessary permits and licences should be in place, though it is worth checking whether any of them need re-certification and/or re-application when the business changes hands.
The tourism industry operates in a highly regulated environment. This requires at least an awareness and understanding of many areas of compliance. It often also requires participants to undergo training to obtain the necessary licences before you can open the doors.
It is recommended that you contact the industry association for the particular sector to determine exact requirements. For a moderate fee, or for the cost of membership, they can help guide you through the maze of legislation and permits often required.
There is also the Australian Business Licence and Information Service (ABLIS). It can help you to identify which government licences or codes of practice are required to operate. ABLIS brings together licence information from local, State and Federal governments.