For the other thing with the pagetree,
yes I tried that as well.
I’ll try again tomorrow but when it didn’t work with the auto-generated pagetree it occurred to me to try explicitly create the pagetree and nothing changed.
I think you have perhaps neglected to heed a key instruction in the tutorial: “Create this file in DrRacket, save it, and start the project server in that directory.”
From the image you posted, it appears that your sample pages are in the directory pageNavTut, but you started the project server in the parent directory of pageNavTut (?)