How can I have a career in education if I studied something else?

HOw did you study in so many countries? Do you mean you went to local schools or intl ones or IB ones? I don't know abotu Canada, but iin the US, plenty of people get into teaching later on in life. They have careers and then use those in the clroom. They teach in HS or uni. YOu'll have to do a bit of research and see if that's possible in Canda?