Hi there and welcome
Can you please power off the Mac
Then hold the left SHIFT key and with it held down, power on the mac.
Keep shift held down until you are at the sign in screen and try to sign in
Let me know the results please
Can you do the following please
Shut down your Mac.Locate the following keys on the keyboard: Command (⌘), Option, P, and R. Turn on your Mac.Press and hold the Command-Option-P-R keys immediately after you hear the startup sound.Hold these keys until the computer restarts and you hear the startup sound for a second time.Release the keys.
Tell me if it now starts up
ok, it should not have gone to Disk Utilities, which means you only seemed to press CMD and R
Can you repeat the instructions and make sure please you are pressing all four buttons
ok, in Disk Utilities
Click the First Aid tab.
Click the disclosure triangle to the left of the hard drive icon to display the names of your hard disk volumes and partitions.
Select your Startup Disk (usually named "Macintosh HD").
Click Repair. Disk Utility checks and repairs the disk.
Let this complete and when it has, tell me if you still have the problem please.
ok, do it on the others and tell me if hat then helps please
ok, it looks like the hard drive has crashed.
Try to do a restore from backup
What then happens?
ok, we need then to attempt a reinstall, it will not touch your files but programs will need to be installed again.
Choose to do a reinstall please
ok, not possible in this state, but attempt the reinstall please
or you just did?
Thanks meaning it is up and running now?
Please let me know if you are still working with me on this