If you want to visit Ontario, then you would know the sites you want to see. Will you rent a car or take a train/bus/plane between locations. FYI - Toronto is in Ontario.
You gotta do some wet work here. Ontario is massive. 1.5 x the size of Texas. As mentioned there is the city of Toronto, and then there is the Province of Ontario, which is in Canada . Toronto is in Ontario. . No one knows where you want to go in Ontario. Northern Ontario ? Capital Region ? Southern Ontario ? Thousand Islands ? You driving ? Flying ? Train ? Hitchhiking ? It is your trip, thus your itinerary .