Is It possible to write text with the keyboard in the note page …can’t do anything in that page…
Maybe clicking that blue “e (edit)”-icon (upper left corner) helps?
As @Kai_Schwirzke already pointed out, that was a user request back in time be able to “lock” notes / “hide” editing button toolbar. Therefore with that “e” u can toggle… 
Here, also Mac, a single click in the empty space does the magic. One difference what I see from your screenshot, your zoom slider is far right, while mine is far left.
… something is ringing. So, you click to the empty space and you cannot write it, right? Is the Window placed on the second Monitor?
Michael.
Oh Boy you are right.. it’s Working now..thanks