Wow, that's a tall order - 2 adults & a dog, mast & sailing rigging, in a boat that will fit on top of your car. And being in northern British Columbia I would imagine that the water is pretty chilly up there, so you wouldn't want to get too wet, or worse yet - take a dip. Get something that emphasizes stability over speed and esthetics. High freeboard to keep the water out. You'll get drenched in a Sunfish.
I agree with the above advice, look for something used to experiment with to see if you like it first. I learned sailing on an old Sunfish before getting a little bigger boat. Good luck, once you try sailing the bug will bite you and you're hooked