Upvote:8
You do not need to fly directly to France.
As a Canadian, you don't require a visa to enter the UK, so it's fine for you to fly through London.
France and Germany are both part of the Schengen area, so they effectively have unified immigration control. If you travel through Germany to get to France, you'll go through passport control in Germany rather than in France (you may be checked on the train, but it's not usually automatic). That's also fine.