I posted this thread a couple years ago but that thread is now closed.
A complaint from Canadian students at McGill is that many American students, even dual citizens, know very little about Canada. I would suggest that you do some reading, even if it is just Wikipedia articles, to get up to speed.
Learn about the parliamentary system and other aspects of Canadian government. For example a province can choose not to abide by a Supreme Court decision; several provinces have public Catholic schools; most private schools, secular and religious, are subsidized by the government. That all sounds very “un-American”.
Also read up on the unique history of Quebec and Montreal . Learn why there are two major English universities in a French speaking city. You will hear about Bill 101. You will be a part of Montreal’s 400,000 strong Anglophone minority, which has a long and turbulent history. Learning a few words and phrases of French would be helpful. If you studied French in high school Montreal would give you an opportunity to expand that knowlwdge.