Seek are a major Job Search company and they’ve put together a resource to show you which jobs are in demand by state, so you can see where the jobs are right now.
You can search by industry and role, and you’ll be able to see how many new job ads there are in those roles over the past few weeks and months.
This resource will give you a short term glimpse into where you could apply for a role right now, and doesn’t predict long term trends. If you’re looking for a job today and not sure where to go then check it out, but don’t use it to choose your uni degree or if you’re going to be on the job market in 6 months time (ie. when you finish Year 12).
For longer term predictions use a tool like Labour Market Insights from the Australian Government. Their data is slightly out of date (for example, right now they’re saying cafe staff are in high demand…) but will give you a better idea of where the jobs are likely to be down the track.