Moving to Australia

I'm a fully qualified maths secondary school teacher from Ireland in my late 20s. Have a bachelors in maths and masters in education and will have 3 years experience working in schools in Ireland.

I'm potentially thinking of moving to Sydney or Perth for 2027 academic year and have a few questions that someone might be able to help me with.

As I would like to probably ease into moving to a different country, what is the short term casual subbing job market like in either of these cities?

After a month or two, I would probably want a bit more routine and security, is there scope for short-medium fixed term contracts rather than going day by day or week by week?

I'm aware I will obviously have to get accredited by the relevant teaching council, however in Ireland, it is still possible to do a certain amount of subbing without this, can this be done in Australia?

If anyone has any experience of making a similar move or can answer any of the questions that would be great.