In my point of view, the most important thing for improving English is yourself instead of the environment. You can find a lot of free ESL or LINK classes in big city. Also it's better for you to get more information and get to know friends in big city. Vacouver is a nice place to live as well as study. The consuming level is lower than Toronto. If you want to go to university, you can choose McGill, which is one of the best universities in Canada.