Question about Canon EF 70-300mm F/4-5.6 IS II USM

The subject goes on your camera. It's a good lens, not too heavy, with a long focal length that, with the crop factor, becomes a 480mm telephoto on your camera. However, I don't think it is particularly suitable for freehand wildlife photography, which often takes place in less than optimal light. Even at a focal length of 105 mm, the speed is only f/5. But if you use a tripod (even a monopod), then it looks different again.
LG Ruedi

You can use the lens with your 80D without any problems. If you look purely at the price/performance ratio, I can give you a clear buy recommendation! I don't know if the speed is enough for you. There are always (usually) better lenses, but they cost many times more! I am satisfied with my purchase and use it more and more often. Just remember that for wildlife photography a longer focal length would help, especially with wild animals.
LG Tobi