I believe your problem is a little different than the other posts you have read. At the moment, this is your most significant problem:
This is almost certainly the source of the issue:
This can definitely break things, and can often be difficult to fix.
This is correct, the KDFONTOP error is not significant. You can fix it or not fix it, it won’t have any effect on the current state of your device.
The device you have typed there is typo’d, for starters. Also, did you actually create a directory at /mnt/nvme0n1? You cannot mount a device on a directory that does not exist.
From the live environment, run lsblk -f. This will help clarify what partitions are what. In the live environment, connect to the internet, open a browser, and log into the forum. Paste the terminal output from lsblk -f here into the thread so we can see what it says.
This is a helpful guide for setting up a chroot (manually) from the live environment and reinstalling the Grub bootloader:
As you follow the guide, copy the terminal input and output and paste it into the forum here.
In your case, after you install Grub you should also attempt to bring your system up to date:
garuda-update
Again, paste the input and output into the forum thread so we can see what is happening.
If the terminal output grows too lengthy for a forum post, use the PrivateBin link in the upper right-hand corner of this or any other forum page. Put the terminal output into the paste bin and add the URL they give you to the forum thread.