A couple of pointers …….
1. If you are hoping at some point to work in Canada (and I’m sure the same will apply for Oz) you will need a work visa or permanent resident visa. To get a work visa for flying will be neigh on impossible which means you’ll need a permanent resident visa. This is a timely process (at least 1 year) and works on a points system of which you need to get the required amount of points and unless you are a professional; e.g. engineer, you’ll be unlikely to meet the requirements. Ten years ago it costs about $1500. However, if one of your parents is Canadian then you’ll automatically be granted Canadian citizenship so all the above goes out the window and you’ll be able to walk straight in and start working!
2. For commercial operations e.g. air taxi you will need the MEIR. A few exceptions include instructing, crop spraying, float planes etc.
Good luck with it all. Don’t worry about the maths too much it’s not that difficult. 24 is a good age to get into it. I concur with most of the posts above.
CG.