If you want to keep studying, you need to extend your study permit. You should apply to extend your permit at least 30 days before it expires. Make sure your passport doesn’t expire at the same time. You can’t extend your study permit beyond your passport’s expiry date.
If you apply before your permit expires, you can stay in Canada under the same conditions as your current study permit until you get a decision.
You should apply to extend your study permit if you plan to travel outside Canada and your permit will expire while you are travelling.
Alternately, you may apply to extend your study permit, apply for a work permit, if you finished studying and are eligible for a post-graduate work permit, or apply to change your status and stay in Canada as a visitor or leave Canada.