Also, sometimes the default "load operating system" menuentry doesn't
correctly auto-detect your configuration, from the partitioning and so on on
the drive. if you come across that issue, see the first link I gave, which
shows you how to modify grub.cfg. You can use that to add a custom menuentry
for whichever configuration you have installed on the HDD/SSD
Where FSF-endorsed distros are concerned, I highly recommend using one of
these guides for full disk encryption:
https://libreboot.org/docs/gnulinux/encrypted_trisquel.html
https://libreboot.org/docs/gnulinux/encrypted_parabola.html