I think Carlton in Ottawa has a good international affairs type program, but I'm not sure. You'll have to do some research.
Declaring a major is just something you kinda have to do, its always possible to change it if you find yourself more interested in other things, unless you already have a good idea of where you want to end up.
i'm interested in international affairs, mostly political stuff to be honest. maybe sociology, i'm not quite sure yet but it's something along those lines