Few quick questions as I have never flown AC or thorugh YYZ before.

I assume I check-in at the United counter? I don't believe I have seen an AC counter at Philly before. If I see a kiosk, that would work.

Since we are connecting onto an international flight, I gather we do not have to get our bags and re-check them. We do need to clear customs (B according to the video).

We have a short connection and just want everything to go smoothly. Thanks