I created an additional user account but that won’t log in. Password is correct but it basically says no.
I’ve tried to login as su but that won’t work either.
I deleted (stop laughing at the back) the original account. No major dramas, I can install again, lesson learned, but can I recover it somehow or boot as su?
You can reach the first virtual console by pressing Ctrl+Alt+F1. From there you can switch to other virtual consoles with Alt+Fn (n = 2, 3, …, 9 = X-Display).