If you apply for an initial study permit outside of Canada, you do not need to apply separately for a TRV. If your study permit is approved and a TRV is required, you will be issued a TRV along with your study permit.
If your TRV has recently expired or you have received your extended study permit, you can apply for a TRV inside Canada.
Travelling outside of Canada during your studies
If you plan to travel during your studies, you must have a valid study permit and TRV to return and re-enter Canada.
If you have no intentions to travel
A valid TRV is not required as long as you have a valid study permit; however, it is highly recommended to keep your TRV valid in the event of an unexpected trip abroad.
Travel to the United States
If you have a valid study permit or work permit or hold valid visitor status in Canada, and you leave Canada and visit only the United States, you do not need a valid TRV to re-enter Canada, provided you return to Canada by the end of the authorized period of your stay in Canada. [See the Immigration and Refugee Protection Regulations, Part 9, Division 5, Section 190(3)(f)].