According to IRCC, if you are going to school for less than 6 months, a visitor visa is sufficient. If your schooling in Canada takes longer than 6 months, you need to apply for a study permit.
Note that a study permit is not a visa for travel into Canada. You may also need a visitor visa or an electronic travel authorization (eTA). Immigrate Simply will complete the forms you need based on the information you provide.
A designated learning institution is a school approved by a provincial or territorial government to host international students. All primary and secondary schools (Grades 1 to 13) in Canada are designated learning institutions (DLI). Post secondary schools (universities, colleges, technical schools) that host international students are chosen by provinces and territories. A list of Designated Learning Institutions at the post-secondary level is available here
There are some exceptions to the need to attend a DLI, however if you are not sure whether you qualify, you should discuss with an immigration professional.
A minor is less than 18 years old in:
Alberta, Manitoba, Ontario, Prince Edward island, Quebec and Saskatchewan
A minor is less than 19 years old in:
British Columbia, New Brunswick, Newfoundland and Labrador, Nova Scotia, the Northwest Territories, Nunavut and the Yukon
If an applicant is less than 17 years of age at the time of application, a custodian in Canada will continue to be required. The applicant must submit a notarized declaration signed by the parent(s) or legal guardian(s) in the country of origin, as well as one signed by the custodian in Canada, stating that arrangements have been made for the custodian to act in place of a parent. Officers must be satisfied that adequate arrangements are in place for the care and support of the minor student. The parent(s) or legal guardian(s), and the appointed custodian must acknowledge that the custodian will reside within a reasonable distance to the minor applicant’s intended residence and school. The custodianship declaration should include the information and signature of both parents, where applicable.
If you have already obtained a study permit, check the expiry date. You can find the expiry date in the top right corner of your permit. The expiry date on your study permit tells you when you have to stop studying and leave Canada.
IRCC recommends you apply for a study permit extension at least 30 days before your study permit expires if you want to keep studying in Canada.
The expiry date is found in the top right corner of your study permit. After this date, you have to stop studying and leave Canada or apply for a study permit extension.
If your study permit expires and you haven’t applied for an extension, you must leave Canada. IRCC information regarding study permits is here.