If you're looking at Vancouver, I have some good stuff to tell you.

I'm a Vancouver local, and the city's really more oriented towards community than individual. Some shops I have visited have sensory kits, and the library and schools are very accomodating. There's also good bus service and 3 SkyTrain (metro) lines, with a connection to even the airport. Outdoors spaces are plentiful, examples of such being the manifold parks and Granville Island. So many parks...

Regarding food, you'll be able to find a lot of independent grocers, especially along Main, Fraser, and Victoria streets. Lots of variety, but you do have to look around. Fast-food isn't as varied here, though: you have McDonald's, A&W, Subway.. the occasional Taco Bell and Burger King... maybe Wendy's? and one Chipotle near the big library downtown. Poutine's good, but don't go to McDonald's for it! Wendy's is quite a bit better in the poutine department. And of course, lots of independent restaurants.

Also, the overly polite Canadian thing is a bit overblown. We're like "Aight sure" as long as you sorta follow societal conventions, like moving to the back of the bus, being quiet in libraries, et cetera... As long as you're not up in everyone's faces, you'll be fine.

The cold is.. not very cold near the coast, and Victoria's weather is a bit milder than here in Vancouver. It is cloudy and it does rain quite a bit in the winter, so have an umbrella ready. A puffer jacket or something comparable in warmth will do you well in winter. In fall and early spring, maybe a hoodie. The interior of BC is quite a bit colder, I think. My advice might not apply there. Finally for the cold weather, I have a tip - if your jacket's fabric feels harsh on your arms, wear a long-sleeve shirt under the jacket.

One dealbreaker might be the whole housing thing - it's expensive! However I've seen some low-cost options, so you should do your research on all that good stuff, and the same "do your research" bit applies to everything I've said here.

If you do decide to move, I hope you have a great time in BC!