Expect a lesson in pronunciation
Don't be offended when everyone you encounter wants to give you an impromptu French pronunciation lesson. People in Lille would turn around in line at the grocery store to gape after they heard me say, 'bonjour." My university librarian once took five minutes teaching me how to pronounce the word for renew, even with a line of impatient students snaking behind me. It was hard to get over feeling foreign when my accent always evoked such curiosity, especially since we don't even flinch over accents in the U.S. But to the French, sharing their language is one of the ways they welcome you.