Utility MacOS

Hello everyone!

I've got a problem.

I need to sell my MacBook Pro with Touch Bar and I decided to erase everything (like suggested by Apple here https://support.apple.com/en-us/HT208496)

I erased my Macintosh HD and tried to reinstall OsX (High Sierra).

Unfortunately it loads the page with the EULA and stuff, but it gets stuck. It gives me "16 minutes" as ending time, but just stays there.

The Startup Disk cannot be found anymore (I run First Aid a couple of times, but it didn't work); I tried to start it from a USB but I can't and I won't let me change the options (since there is no more admin account).

Did anybody have the same problem?

Much appreciated,

Thank you!

Helen