In the comments, @steeling probably meant the
/etc/fstab of the installed system, which might have been available in the initramfs. When running
cat /etc/fstab from a live CD you got the
/etc/fstab of the live CD environment, which is not very useful here.
lsblk -f output indicates that although the
sda disk is detected and seems to have two partitions on it, there are no filesystem types, labels nor UUIDs listed for them. That makes me worry about accidental overwriting or possible hardware issues. It seems that the root filesystem of your Linux installation is no longer readable for some reason.
First, please run
sudo smartctl -a /dev/sda and edit the output into your question. Feel free to hide the serial number and WWN in the beginning of the output, but it would be important to see the disk model and firmware version (to exclude the possibility of known firmware bugs) and the SMART health status and attribute values.
The next useful command would probably be
sudo fdisk -l /dev/sda: its output should reveal the type of partitioning used and the types of the partitions... or if the disk has failed, the command might hang or report an error. Based on that information, it would be possible to plan the next actions to determine what has happened and whether or not it would be feasible to recover data from this disk.
sudo fdisk -l /dev/sda command hangs or produces an error message, you might also want to run
sudo dmesg and see if the end of the output includes anything that looks like an error message.
You should also describe the system a bit more. Is this the first boot-up of a new system just after the installation of a Linux operating system, or has this system been working correctly before this issue started? If the system was working correctly before, do you know what was the last thing done with the system when it still worked?
It might be that the disk has some sort of problem that allows the system to read the partition table, the bootloader, kernel and initramfs from the beginning of the disk, but trying to read deeper into the disk causes it to fail.
If the system contained any files that have significant value and there are no backups available, STOP here and contact data recovery professionals. If the disk has a mechanical failure, further attempts to access it might cause more damage.