From PDX and with no bags to check if you do OLCI and have a boarding pass you can treat it pretty much like a domestic flight (though get to the gate at least 30 minutes before departure)..leave enough time to get through security...Air Canada participates in TSA PreCheck so if you have that you can use it at PDX. From YVR, follow what the others have said..

You most definitely do not need to arrive at PDX 2 hours in advance.. .even if you're checking a bag I wouldn't get there that early as a 1K. They fly small planes between PDX and YVR and the checkin is shared with United. If the bag cutoff is 60 minutes, I'd arrive at the kiosk at PDX no later than 65 minutes before. Not kidding...especially because by then the other pax will have already arrived and checked in..