I’ve reset the NVRAM and the question mark still appears. How do I get to system settings to turn off possible firmware password?

Start your Mac, press CMD +R on booting. You will boot into macOS recovery

1. When the utilities window appears, click Utilities in the menu bar, then choose Startup Security Utility or Firmware Password Utility.
2. Click Turn Off Firmware Password.
3. Enter the firmware password again when prompted.

From the macOS utilities you can also go to disk utility to perform a disk first aid on your disk to see if this is really the HDD failing (I think it is)

It's likely your hard drive has died.

If your Mac starts up to a question mark - Apple Support

If the question mark is persistent

If the question mark stays on your screen and your Mac does not start up normally:

1. Press and hold the power button on your Mac for up to 10 seconds, until your Mac turns off.
2. Every Mac has a power button. On notebook computers that have Touch ID, press and hold Touch ID.
3. Use Disk Utility to repair your startup disk. (Follow the steps for a Mac with an Intel processor.)
4. If Disk Utility found no errors or repaired all errors, reinstall macOS.
5. If you still need help, please contact Apple Support.