MacOS utilities

It sounds like you're in Recovery mode which is where you need to be.

If you've erased your Mac with Disk Utility and named the internal HDD, then quit Disk Utility.

Make sure your Mac is connected to the internet preferable by ethernet cable to your router or by wi-fi. (You can click the wi-fi icon in the menu bar upper right on your screen.)

Then click Reinstall macOS from the on screen menu and follow the prompts to complete the reinstallation.

How to reinstall macOS - Apple Support:

https://support.apple.com/en-us/HT204904

Well, I have the same problem and I tried restoring but my disc is completely locked, how do I exit Utilities now?

To exit from macOS Utilities when you are in Recovery mode, click the Apple logo  (top left) and then select Restart or Shut Down. Or you can click Quit from the Utilities menu bar.

Would you like to share the problem you are having with your Mac? Maybe other users can offer help.