Thank you everyone for your replies. Thank you for not being as mean as other places online for travel questions, too. >.>
The train isn't until October, but I'm trying to get this sorted to the best of my ability before the trip. I've never taken public transit before, and I haven't been out of the country since 2005 (I'm an American). No, I suppose that the tickets aren't meant to be instructions, but when they give you instructions for most of it, and not part of it, it does raise questions, I would think.
I am getting the impression that I simply remain on the train, but I'm not quite sure. The website is confusing. I did get a ticket with a QR code from SBB. Just the one.
There is this note from SBB:
"Important information on regional trains in Italy.In Italian regional trains, an automatic check-in takes place at the scheduled departure time. The digital ticket can be obtained through the partner railway. An internet connection is required."
Which makes it sound like I just visit the train station once I get off in Domodossola, but I figured it wouldn't hurt to ask, because this is very new to me.
The train is R 2407. The departure time is 12:55 from Domodossola, and it's on 10.10.2026