Thanks so much for both those replies! Just another quick question, how early on into my degree would I need to decide that I want to do an extended major in psychology? (If I wanted to work onto becoming an accredited psychologist)
When you do all the enrolment stuff for Monash, they do ask you to nominate your areas of study, but this is not set in stone.
For example, at the start of my second year, I had nominated Psychology as my major, but in the middle of the year, I changed it to an extended major. I then picked my units to qualify for the extended major instead. Even now entering my final year, I could switch back to just a major if I wanted to and alter my unit choices accordingly. Just recently, I added a nomination for a Philosophy minor because it turns out I was on my way to completing enough units for it, despite having never planned to a minor in Philosophy at all. Your unit selection is what determines your majors/minors in the end.
This probably won't make much sense to you right now, but once you're in uni, it'll make much more sense after a semester or two. There's also course advice services and your faculty help desk to assist you in structuring your course and guide you through any changes you wish to make regarding your decisions about majors/minors once you're a student.