For Ontario, if you are visiting Canada you can use it for 90 days. But if you are moving here for good you’ll need to get a Canadian driver’s license within 60 days. Could be different in other provinces.
If you are travelling and rent a car, the car rental company offers insurance - it’s quite expensive but I remember it’s the same rate for Canadian and non Canadian driver’s license. Not sure if you can get an insurance for your own car though.