I am curious about the most economic way to travel from Canada to and through Europe and was thinking to load camping gear into a hatchback and put it on a ferry to somewhere in Europe (e.g. Hamburg, Germany) together with us inside. Where can I find information on how to do this?
Well, there is no trans-Atlantic ferry service, direct or connecting so what you're asking is simply not possible.
The closest you could get is shipping the car as cargo and booking yourselves on the same ship as passengers.