Boot issue after reboot - mounting /etc error

Hi, I encountered this issue after rebooting during normal daily use of my PC. I have uninstalled the Dropbox app, installed some ROMs, and played video games.

I tried to access the partitions using a Live Mint OS, and I can mount one of the two partitions. So, the HDD isn't broken.

The partition that I can't mount is the primary partition: nvme0n1p1. I don't know why only the second partition, nvme0n1p2, seems mountable.

I searched inside it for the boot folder of the nvme0n1p2. It exists, but there aren't any files inside.

Maybe I have to understend better how to mount the nvme0n1p1? Maybe I need to restore the boot from BIOS? I don't know how to set the boot file from BIOS.

I disabled CSM Secure Boot from BIOS.

Can someone help me?