Your PR status is being activated the day when you receive the Confirmation of Permanent Residency (a PDF file) in your online account (its called e-landing) or at the border. That means you have become a permanent resident of Canada. Based on this document, you also receive a Permanent Resident Travel Document (a card that allows you to freely enter Canada since you have PR status). This card is issued for 5 years.
Recently, there have been delays in issuing this card. After being granted permanent residency (receiving the Confirmation of PR), you would typically get the card within 10 days by regular mail. Now, many people wait several months. Sometimes it's simply forgotten to be printed, and other times it gets lost.
If you haven't received your PR card within 6 months of obtaining permanent residency, you need to reapply. The package you need to submit is called:
Solemn Declaration Concerning a Lost, Stolen, Destroyed or Never-Received Permanent Resident Card