Done - thank you so much!!!!!
My current kernel is now 6.17.0-20-generic. Can I safely / Shall I update it?
Stupid question: Do I need the NVIDIA driver (it's a spare pc that's only used from time to time to check emails, provide online access, print documents etc.)?
If you don't miss anything now and it works as you want, then you don't need the nvidia drivers. Test if you can play videos in browser if you want to watch some.
Perfect, then it's been enough experimenting for today... thank you again for helping out so quickly!
When You don't have the Impression of slow Performance for what You do, you can of Course stay at the Nouveau Driver.
If You should have something like this a Tip for a quick Test: Your System should now run by default in Wayland. When Problems happen, go to the Login Screen. click there on Your Profile so that the Password Field appears. When it is appeared, you should see a Gear Icon in the botton right Corner. Click on it and choose the Option ''Zorin Desktop on Xorg'' and then log in.
Because of a current new released 7.0 Kernel that bring some Issues with it, I would suggest to use the Software Updater to update the System and look if there are update Files for the 7.0 Kernel untick them.
Or You install the Kernel and when You get Problems, You can go back to the older Kernel. How You handle that, is up to You.