Since you are traveling to QC, and presumably to one of the two major cities (Montreal or Quebec City), learn the following two phrases and use them:

Je ne comprend pas (I don't understand) ("Juh neh comPRAHN pah")
Parlez vous Anglais? (Do you speak English?) ("PARlay voo OnGLAY?")

and, of course, Merci (Thank you) ("MerSEE")

Certainly in Montreal and mostly in Quebec City, folks are predominantly bilingual and will appreciate that you made the effort to learn those phrases and are asking them politely to speak English...many US'ers arrogantly just speak English to locals and presume the response will come in kind. My experience on many trips to Francophone Canada is that this simple effort is greeted with an appreciative smile and good service in reply.