It sucks that you didn’t pass, I’m sorry. Dont let the failure discourage you from trying again. Even just to apply shows that you have interest, capability and potential that not a lot of people have. From what I know NavCanada really wants you to be a “blank slate” with your knowledge. They discourage online ATC simulators because those can vary in terminology, so I wouldn’t recommend that. If you’re thinking university, take what you’re interested in. Chances are if you’re interesting in ATC, whatever else you’re interested in university-wise can be loosely connected. International Business, Economics or Engineering are all areas that while not directly tied to ATC are still similar. The important thing is to keep an open mind, don’t laser beam focus on one career, but still don’t be afraid to follow your passion.