At Gare de Lyon you will only have to scan your ticket to acces the platform, then you just find your carriage and seat.
Then when the conductor comes he will again just scan your ticket. He normally does not need to see your ID.
After the Mulhouse stop Customs, and sometimes Border Police boards the train. Customs will just ask if anyone has something to declare, and might at random ask you what you have in your luggage. Border Police will mostly only be on the lookout for suspicious people. So they will probably not bother a Canadian tourist.