Android TV Navigation (opens in new tab)

How does one navigate Android TV using a keyboard and mouse? There seem to be so many cul-de-sacs where one goes into an app or Settings and then can't get out\. I have tried all of the usual key combinations including ESC, back arrow, up arrow, down arrow, Ctrl-Alt-Del etc etc etc\. Nothing seems to work\. I am constantly having to re-boot the Raspberry Pi to get back to the home screen\. If I connect this to the TV then I will have to use a wireless keyboard\. Currently using an ordinary PC...