Overall, Canada is a secure country. But that's not a reason for doing anything you like!
During your trip to Canada, safety isn't going to be a major worry. The whole country is safe and there is no particular or specific danger that you need to dwell on.
On the other hand there are three characteristics of Canada that you should never forger: isolation, wildlife and the weather! The first requires a certain amount of forethought if you are going to places that really are cut off from the rest of the world (thenorth of the North West Territories, certains parts of the Yukon …). The second requires you to know how to prepare, and how to behave should you happen to meet a bear (for example...). The third requires the correct equipment, especially when the temperatures go below 0°.
Apart from these three points, the towns are generally very clean and there is a clear police presence. You might need to be careful if you go to East Hastings in Vancouver.
Like everywhere, some advice is "just" common sense during a trip, even in Canada: don't leave valuable objects visible in a car, don't leave your money in a pocket that is easily accessible and don't wave large wads of cash around in front of people - opportunity makes the thief!
In the same way, be careful how much alcohol you drink in some areas of the country and be careful not to roll home from any old bar in the early hours of the morning. Don't walk down dark, deserted alleyways and always use public roads and transport.
Just like everywhere, be careful how you behave. Don't send out "I'm a tourist" signals and you should have no reason to be worried about your security during your trip toCanada!