Windows 11 New PC - must I install Win10 then upgrade to 11, or can I go straight to 11?

Hi @Mushman,

You can go straight to 11.

Cheers

your key for Windows 10 will stay on the current system [by default]
the new PC that arrives tomorrow will have its own key [normally] or be a blank system with no OS... what you can do is sign in with the same Microsoft ID [email + password] to link this new system to the current account and that means files, desktop background and some other junk like movies you got from the Microsoft store will sync to this new system without you having to copy paste files into a Usb stick

a key is [generally] one per computer unless you have Enterprise accounts that [in effect] rent keys for a company