Any major city in the world has crime and “back alley” problems. Canada is no exception. Toronto has plenty of crime. And there are lots of places you should not go.
Toronto PD puts together nice maps: https://data.torontopolice.on.ca/pages/maps
Ontario has one, too: https://www.ontarioca.gov/Police/CrimeMap
You can find this stuff by using your favorite search engine. You can usually find which neighborhoods and streets you would want to avoid.
Go to town with google like I did and find what you want.