EDIT: As it turns out this is just how gnome is supposed to look and to get a permanently visible dock showing running apps and favorites I must install an extension like dash-to-dock
Thanks everyone to help me understand I was the problem here ๐
After using Ubuntu for years I thought it would be a good idea to try out plain old Debian for the first time.
So I downloaded the live-Image setup a VirtualBox and started installing it... installation ran trough without any problems. But I don't see any panel/taskbar anywhere.
I tried to google this and best guess was that gonme-panel was not installed (how?) after installation I tried to run it by the terminal but it only trows an error "(gnome-panel:3427): GLib-GObject-WARNING **: 20:24:58.712: invalid cast from 'GdkWaylandDisplay' to 'GdkX11Display'". So before I start digging into this I just wanted to confirm that I am on the right track and not just mixing stuff up. So does anyone have an idea what went wrong here?
So... I haven't routinely run gnome in decades and only use wayland on one machine as a frequently-disappointing experiment, but that sounds distinctly like gnome-panel is starting for the wrong graphics backend.
Are you starting your graphical session from a manager like GDM or by hand from the console, and do you know if it's an X or Wayland session you're in?
I think you're running a wayland session and for some reason gnome-panel is trying to start in X11 mode. Try running "GDK_BACKEND=wayland gnome-panel" at a terminal to force it, and see if it starts? (Or, conversely, you might need to set GDK_BACKEND=x11 because you're in an X session and it's starting in Wayland mode, but my first guess is more likely).
This is not an entirely complete answer because I'm not sure why it would be picking up the wrong environment or how to make sure that is configured properly in general.
It seems that how gnome is coming in Debian 12 it is coming without a permanently visible dock. (Yes I know sounds crazy) so there was nothing wrong with the system the error probably just occurred because I (re)installed gnome-panel in an attempt to fix something that was not broken.