I'd suggest not wiping the computer yet and try to re-run the installer on your current installation. Chances are that it worked for you as well and save some time.
So, this is what I did:
1. Download the Mojave installer to my computer:
Download macOS Mojave by Apple on the App Store. See screenshots, ratings and reviews, user tips, and more apps like macOS Mojave.
apps.apple.com
2. Create the installer media in the USB drive:
You can use a USB flash drive or other secondary volume as a startup disk from which to install the Mac operating system. These steps are primarily for system administrators and other experienced users.
support.apple.com
E.g.
Mojave:*
sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/MyUSBVolume
3. Boot using the USB drive (Hold the Option key during the boot immediately after the chime).
4. Choose to install over the same drive. Don't need to open disk utility at all. Just press Next and let it complete.