We (my daughters and I) are also Canadian citizens (actually dual) living in the US. Both daughters applied to some universities in Canada, and one attended university in Canada. I also have relatives who went to UBC although my daughters and I for our bachelor’s only applied to schools much further east.
My understanding is that admissions is based primarily on your two most recent years. If your sophomore and junior years are both very strong, then your chances are excellent. If your sophomore year is so-so, and your junior year is strong, then there is a chance that they might wait for at least your midterm senior year grades and admissions is still possible with two strong years. This last part I have not seen at UBC (my relatives who went there were strong students for all of high school) but I had some friends who had this occur at other Canadian universities.
I do not think that a C during your freshman year of high school will be a problem.
My understanding is that medical school in Canada works the same as in the US, in the sense that you first need to get a bachelor’s degree, and then apply to medical schools.
The fact that you are a Canadian citizen will help you in at least two ways. First you will be paying tuition as a Canadian citizen while you get your bachelor’s degree. Also, my understanding is that it is exceptionally difficult for a non-Canadian to get admitted to medical school in Canada.
We had a couple of schools miss the fact that my daughters were dual citizens, and along with an acceptance also send information on how to apply for a student visa along with cost information for international students. We called and they had us fax them either a copy of the student’s Canadian Passport or Certificate of Canadian Citizenship. This cleared things up very quickly and easily. Do you already have either a Canadian Passport, or a birth certificate showing that you were born in Canada, or a Certificate of Canadian Citizenship?
There are some other Canadians on CC, some of whom are from further west. If you post your GPA for each year of high school then this might help some of them chance you.
Also, my understanding is that admissions to medical school in Canada is quite competitive, and is at least as competitive as admissions to medical schools in the US. It is generally a good idea to have a “plan B” in case medical school does not work out.
Best wishes and good luck with this.