You have more than enough time to accomplish the transfer at PEK and have a cushion of about 3.5 extra hours in case there are delays on the domestic. This will be entirely in PEK Terminal 2 so no need to switch terminals--that eliminates one layer of effort. CZ almost certainly will not agree to check your bags through but this shouldn't present any problems, and no need to do all carry-on if it doesn't fit your travel style/needs for this trip.

So procedure is to just check in at CAN for the domestic, give them whatever luggage you want to check. Pick up at the assigned Bag Claim Belt at PEK (luggage handling is usually fast, and flying F should allow your bags to be tagged for Priority handling). Then you'll need to head into the main arrival hall and upstairs to Departure level. Look for the International departure signs (which are also in English). First step is to show the gatekeeper security fellow your passport and printout of your outbound intl ticket confirmation, then you'll be let into the Check-in area with a walk-through of Customs inbetween. Customs will occasionally pull people aside for a luggage check, but normally do not bother foreigners. Find your assigned DL desk, check in and get boarding pass, then proceed to Immigration followed by Security Checkpoint. Then you'll be on the secure airside and can go to lounge or wherever until boarding time. Nonstop flights to USA are subject to additional security procedures: a manual luggage inspection may happen in Delta's check-in area, and a carry-on inspection will almost certainly happen in the boarding gate area. They will be mercilessly strict about confiscating liquids over the 100 ml toiletries limit, including drinks purchased in the secure airside part of the terminal.

There is not a lot to do in the secure airside of any PEK terminal, so if you don't have lounge access or don't have something to keep you occupied, you might want to stay on the nonsecure side after you arrive from CAN, and check out slightly better restaurant options, Starbucks, etc.