#1

I followed instruction https://docs.fedoraproject.org/en-US/fedora-silverblue/installation-dual-boot/
After a few quirks I can boot on Silverblue, but I have no users.

At first it repeatedly started Initial-Setup (very annoying). But I did this:

Add “InitialSetupEnable=False” under [daemon] in /etc/gdm/custom.conf

Now I can confirm, I cannot login as a user, from Gnome or a console (Ctrl-Alt-F2 …) is working.
(Of course, I cannot remember the root password…)

#2

Yeah, that’s pretty important… Try booting into another Linux live CD and clearing your root password in /etc/passed, then booting back into Silverblue. Once you can get to a shell with your root password, use the useradd command to add a new user.

That being said, are you sure you completed the steps during the installer to set up a user and saved them?