If you have typed C-h and decide you don't want any help, just
type C-g to cancel it.
+(Some sites rebind the character C-h. They really shouldn't do this
+as a blanket measure, so complain to the operator. Meanwhile, if C-h
+does not display a message about help at the bottom of the screen, try
+typing M-x help RET instead.)
+
The most basic HELP feature is C-h c. Type C-h, a c, and a
command character or sequence, and Emacs displays a very brief
description of the command.