score:3
You can find more information at https://www.aircanada.com/us/en/aco/home/plan/baggage.html
Of course depending on your type of ticket, your free allowance may change. If you are in Basic economy (yes United/Lufthansa/AC do sell Basic Economy even in International sectors sadly), you may not be allowed any free allowance except a personal item.
You may find specifics of your allowance at https://www.aircanada.com/us/en/aco/home/plan/baggage/checked.html or by clicking on 'My Bookings' tab at https://www.aircanada.com/us/en/aco/home.html#/home:
If you have already done this step, the best information will be available by reaching out to them. More information at https://www.aircanada.com/us/en/aco/home/fly/customer-support.html