SIM card

We will be travelling for two weeks through the provinces of Ontario, Quebec, New Brunswick, and Nova Scotia. I would appreciate any recommendations for a cell phone SIM card that provides calling capability only, no texting or streaming needed. Where would be a good place to buy one and what carrier would be best? We will be using a ZTE throw away cell phone. I've also read that 7-11 and Petro Canada sell inexpensive phones with SIM cards, would this be a better option?

Thank you for any advice you can offer!