No you do not need to go to a port of entry. You only need to print, date & sign your ECOPR (the Client copy that also has the Immigration Officer's signature on it) and keep it ''forever' ... you may need it when you play for Old Age Security or other future benefits.
You can then use that ECOPR document to update or apply for a SIN number at Service Canada (or online), Provincial Healthcare, status as a student who can pay domestic fees going forward (instead of international fees), update bank status (if, for example, you have a credit card that required security because you only had temp status), etc.
You cannot use the ECOPR to travel -- you need to wait for your PR card.