Does it look bad if you take an AP exam before the class?

But not most.

And it’s moot in this case; OP is from Canada. Which likely also means they will have less flexibility on when to take the course and/or options outside the HS

Agreed, that’s why I said some. To put a finer point on it, and IMO of course, relatively more colleges consider CS as a core course than as a foreign language..

I can’t take them in Grade 10. I can take them in Grade 11, if I do summer school to knock out the prerequisites, although I’m not sure if that’s even a good idea.