Deleted through Disk Utility

It sounds like the drive was formatted and the new macOS was not installed completely before restarting. Power down the computer and restart into macOS Recovery. Instructions are contained in the article(s) below.

You will almost certainly need to boot into Internet Recovery mode in order to access macOS Recovery. Internet Recovery will reinstall the original macOS that came with your computer so you can leave it like that or update it to its most recent macOS version.

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

^Question Mark at Startup^

About macOS Recovery - Apple Support

^macOS Recovery & Internet Recovery^

Please explain the exact steps you took; it sounds like you deleted your startup OS which you really cannot do while you are booted into it. So you deleted a partition or volume or were booted into another partition?