after upgrading to Sonoma files have disappeared

the steps:

1. I have a brand new MacBook Pro which I started to set up today. M2 Max, 2023 16". I used Migration Assistant.
2. I upgraded to Sonoma. Went slow, but without any errors or warnings.
3. Maybe five third party software packages required updating, including small things like Bartender and bigger ones like Photoshop. I did all that.
4. At that point I realized both the desktop folder and the document folder had disappeared from the finder sidebar. Well hidden, despite serious search for them.
5. I restarted. No change.

I searched here and other places with the tag line "“Desktop” can’t be opened because the original item can’t be found."

I followed suggestions:

1. I tried to delete the finder prefs file, but I was refused permission.
2. Tried to update permissions on the iCloud end, but I got a denial. Multiple denials.
3. I relaunched the finder.
4. I went back into iCloud and made sure, yes, Desktop and Documents (and also Downloads) were still there.
5. Next to each of them was a download icon, the one with a cloud.
6. I downloaded all three folders. It took a good while. I was careful to keep track of subfolders. When that process was done:
7. I restarted. Again when I tried to open the desktop on the laptop I got the “Desktop” can’t be opened because the original item can’t be found error.
8. I relaunched the finder. No luck.
9. I tried turning off iCloud backup for the relevant files. It asked if I wanted to keep copies, and I said yes.
10. Then I couldn't get to the files on iCloud (which I anticipated). Neither were they on my laptop. I turned iCloud back on.
11. And here we are. I suppose it might be possible to open every file now stored on iCloud and then manually save them to the laptop, but I have a serious number of files and the process would lay me low for days. And I need to work.

I hope someone can give me a straightforward set of instructions. I could still reinstall Sonoma, if that's the only reasonable choice.

Please somebody, give me a hint. Thank you for whatever you can provide.

[Edited by Moderator]