In order to study in Canada, you will need to obtain a Canadian Study Permit, which functions as a Canadian student visa for the duration of your stay. If the duration of your course or program is 6 months or less, you do not need a Canadian study permit. Nonetheless, it may be a good idea to apply for a study permit before you come to Canada - otherwise if you decide you want to continue with another program, you will need to leave Canada and apply for a study permit through the visa office.