can someone have a US apple id and a Canadian one?

Yes actually.

You can have different Apple IDs for different countries sure.

What you cannot do, is be logged in to both on a single device at the same time.

Also a single Apple ID can not use the store from 2 different countries at the same time. You can change countries for your Apple ID, but its not a easy or quick process.

What are you trying to accomplish exactly?

Its really not a good idea to have multiple Apple IDs unless there's a very good reason to do so, because management can get complex.

You will need to different email addresses, one for each account and purchases and data cannot be shared between them in any way except manually.

Why do you want two accounts for different countries? Maybe there is another way to do what you want?

No, you can't have two different locations at the same time.