I use my Canadian debit card in the USA all the time without problem. The ATM networks are, AFAIK, very compatible and similar.
Some POS systems will ask Credit or Debit, but if it’s a valid VISA card, likely it will be treated as a VISA card by stores. Most stores are Chip-ready now and only swipe if there’s no chip or the chip wont work. The credit card issued by my local Canadian bank is also tied to my bank accounts, like my debit-only card. So I stick it in the ATM, it asks DEPOSIT, WITDRAWAL, etc. (If the ATM is not for your bank, WITHDRAWAL is the only option.) then it asks withdrawal from CHEQUING, SAVINGS, CREDIT CARD?
the only other proviso - when I travelled to Europe or the Orient, the warning was that the ATMs wanted a standard 4-digit PIN. Not sure if that is a requirement in Canada, since I always have had only 4 digits. But… be sure your PIN is 4 digits to be safe. (I assume the programming in some ATMs does not handle longer PINs).
My ATM from TD Bank worked fine all over the world, except Egypt and Jordan. They would not even do in-the-bank withdrawals on an ATM debit card, but the ATMs did do cash advances on VISA. In the lobby of the Moevenpick outside Petra I found an ATM with a chip reader and my debit card worked with that. Regular debit worked fine in Europe, in ANZ (a decade ago), in Israel and Turkey.
I don’t know what happens if you try to do debit without a chip at the bank counter. Most ATMs in Canada are still mag stripe readers that take and give back your card, and you will note many have flashing lights around the slot to show you nobody has added a card skimmer to the slot. I have not heard of ATMs eating cards being a problem, but just in case, either cancel when it does not work or have a spare card handy.
(American Express chips don’t work in about 50% of the chip terminals I’ve run across in Canada. I heard from someone that there has been some significant store theft lately using counterfeit Amex cards, since they end up swiping them - much less secure. Her management issued a directive that any card when the chip fails or there is none, and the card must be swiped, they will ask for additional photo ID despite the cardholder agreement.)