My first ? is why are you using GPT instead of MBR disk partitioning, unless the
SanDisk Z400s M.2, or your PC, will not support MBR. I see the EFI partition that is needed for
GPT and should be mounted at /boot/efi. I see no / partition that should be mounted
@ Filesystem Root, I have ran Linux in a VM without a swap partition but a stand alone Linux install would more than likely need a Active Swap partition.
This is Gnome Disk layout for Debian 10. Grub is installed to /dev/sda
/dev/sda1 is bootable and mounted at Filesystem Root
/dev/sda2 is mounted at /home
/dev/sda3 is Swap and active.
Does this PC run Linux only?
Good Luck!!!