Use it like windows. The username and password is your username itself. And for those who have not joined scratch or have not signed in you won't be able to use it.Press the close icon to close anything which has appeared on the screen . i have tried to make it as real as possible . If you wnt to see what Microsoft is actually planning to make windows 11 then click on this link https://scratch.mit.edu/projects/416684116/
thanks to a random person for some audio .