So that flight is (currently) operated by an A350-1000 with QSuites. The seat map is pretty open with only 1 window seat 'taken' at the moment (and 17 remaining available to choose) (see below)

If you're getting an issue finding the PNR, my guess is you're looking at an expedia reference number rather than the Airline booking reference. (They may only give you an AA PNR, rather than a QR one; but AA should be able to give you that if you have theirs)

I haven't booked with Expedia for nearly 10 years, but at the time I got a long number confirmation from Expedia, but at the top of the email which had the e-ticket numbers, it had the text "CONFIRMED" in green, then the airline PNR below/next to that.

I don't want you to post it (or send it to me) but see if there are other 6 character references in the expedia email, perhaps, or at worst case, try and get in touch and ask them for it? (They may give you the AA one and then you may need to get AA to give you the QR one, which is a bit of a pain!