It is said Nine. yes nine as our number nine in America. Nine. Edit: It is spelled nein ;) but the other person is correct you say it like the English word nine
Gerade ich bin
I assume you mean in the sense of browsing in a shop when you're approached by a shop assistant:Ich shaue/gucke nurorIch schaue mich nur um
Nur ein scherz means just kidding.
Just a minute is einen Augenblick in German.