I am in need of assistance understanding how to enter the names of locations in Canada please.

I know Canada has territories and provinces, but how do you record these? Also, are there "counties" within each province or territory? I have searched for these answers without success.

I have many family members who lived in Trois-Rivieres, so how would you list this location? How do I find out where a specific place is located? There are a couple places, at aleast I'm sure they are places, that I have come across in my research but I have no clue where they are geographically.