To boot into single user mode you edit the boot instructions for the GRUB menu entry you wish to boot and add the kernel parameter/option single. Brief instructions for how to do this are below.
Turn on laptop and wait when GRUB menu will appear. Select (highlight) the GRUB boot menu entry you wish to use. Use the first one entry in this case.
Press e to edit the GRUB boot commands for the selected boot menu entry.
Look near the bottom of the list of commands for lines similar to
linux /boot/vmlinuz-5.7.0 root=UUID=bc6f8146-1523-46a6-8b
6a-64b819ccf2b7 ro quiet splash initrd /boot/initrd.img-5.7.0
Change the line by removing quiet splash and by adding the kernel boot parameter single to the end of the line (it should look exactly like this: ro single).
For this example you would change:
6a-64b819ccf2b7 ro quiet splash
6a-64b819ccf2b7 ro single
Press either Ctrl+X or F10 to boot using these kernel options.
Note: These changes are not persistent. Any change to the kernel boot options made this way will only affect the next boot and only if you start that boot by pressing either Ctrl+X or F10 while still in GRUB edit mode.
Then run the system and see errors on the screen and provide a photo of the screen with errors or information the system shows.
Then you should hit Enter to go into maintenance mode and type in terminal.
and hit Enter.
It will show you all information from the boot start process to the end, I mean to the moment you hit Enter to go into maintenance mode. To quit viewing hit q.
Provide screenshots. Use arrows or PgUp PgDown to scroll text in the screen.
Then very important step is to show the fstab.
sudo cat /etc/fstab
Example: how fstab should look like:
UUID=89ef95ac-3c86-4b94-a37c-da8c72a148fa / ext4 errors=remount-ro 0 1
# /boot was on /dev/sda6 during installation
UUID=8b4947b6-c0c9-4b1f-87ed-ef698609be22 /boot ext4 defaults 0 2
# /boot/efi was on /dev/sda2 during installation
UUID=C8CA-DC0F /boot/efi vfat umask=0077 0 1
# /home was on /dev/sda7 during installation
UUID=21f30bb7-2c7a-405f-bb16-b37901eeda09 /home ext4 defaults 0 2
# swap was on /dev/sda5 during installation
UUID=c98dd990-02e1-4872-9de0-d00601e5aa7a none swap sw 0 0
Edit the /etc/default/grub
sudo nano /etc/default/grub
ctrl+o saves, ctrl+x exits
sudo grub2-mkconfig -o /boot/grub2/grub.cfg and restart.
To restart type:
And hit Enter.
Then you can repeat all steps but instead of hitting Enter, hit Ctrl+d to run the system.
See will it load with default options.
The same effect you will achieve when you will hit Enter instead Ctrl+d and then type:
and hit Enter.