There are lots of different pathways for airline work. There are specialist tertiary qualifications or entry level roles such as Airport Check-in where you gain experience and qualifications along the way as you progress within the industry.
Airlines require a full spectrum of expertise roles. Some mid to senior level entry roles may need a generalist qualification such as a Commerce or Management degree. If you would like to specialise in Aviation at university you can study a Bachelor of Aviation Management which will cover all facets of the industry.
TAFE certificates and diplomas are well regarded in the aviation industry. These range from generalist qualifications such as finance or project management to industry specific certificates such as a Certificate in Aviation, Ground Operations or a Certificate in Aviation, Cargo Services. There are also aviation specific training colleges offering training in Ground Operations, Flight Operations, Cargo Operations and Airline Check-In and Reservations systems.
If you feel aviation is the right industry for you, many operations roles are gained by starting in an entry level role and gaining experience and skills as you progress on-the-job.