So, I plan on going to Canada for a student exchange program on my university, maybe even live there. How many years before it I should start getting ready? What do I get? Can I choose the state I will study/live on? How many money do I need to bring there?
Every single one of your questions is dependent on the exchange program. You should go to the program people and ask them. Since you know you want to do it, go ask them now; there is no “too early”.
And especially if you plan to “live there”, do research now. Does that mean you want to work there and stay after university? You’re talking work authorizations, visas, possibly immigration. That is the realm of lawyers and you shouldn’t take any advice from Lemmy users beyond “go do your research”.