Nvidia GT 210 Manjaro 21

It’s the same packages, there are more info though. Also it requires kernel 5.4 or 5.10 no other kernel supported there.

For Nouveau blacklist, maybe you could do as in a default Manjaro Nvidia installation at /etc/modprobe.d/mhwd-gpu.conf:

blacklist nouveau

When I use x11 to log in, I get a black screen with only the mouse cursor. I got into terminal, but I have no idea how to make a .conf file.

For example you can do sudo nano /etc/modprobe.d/nvidia.conf to create this file from terminal. Then you write the content of the file, then you press CTRL+X to save and exit, confirm by pressing Y and ENTER (read the screen at the bottom).

“blacklist nouveau” was added. I rebooted, but the message /dev/sdb2: clean, files 297405/299333568, blocks 5017346/11971182 remained on the screen.