Hey congrats!! That's too bad they never replied to your webforms... but at least they finally got your COPR to you!
I think aside from your passport and COPR, you only need a list of Goods to Follow if you're planning on settling in Canada right away (as opposed to "flagpoling"/just activating your PR and then immediately returning to the US) and you have possessions that are going to be shipped to you at a later date. Someone please correct me if I'm wrong though, since of course I haven't actually been through this process yet.
Not sure which way is best for you, but for weighing your options you could check out this resource
https://britishexpats.com/wiki/Landing_as_PR-Canada and specifically for information relating to flapoling (if that's something you're considering) you can check out this site
https://www.immigroup.com/news/flagpoling-your-way-new-work-or-study-permit-or-permanent-residence
As far as I've seen on this forum, there are 3 questions asked by the immigration officer that are officially part of the "landing interview", and they are some variation of the following:
1. Have you ever been denied entry to Canada?
2. Do you have any undeclared dependants? (confirming whether your list of dependants is still accurate)
3. Have you ever been convicted of a criminal offense in any country?
They will also ask for your list of Goods to Follow, although you do not need to provide it if you are only flagpoling.
Once you've answered the above, you should be all set and officially a Canadian PR.
Hope that helps!