I am an emacs beginner.

I can't find a way to load one of my minor mode automatically.
It's whitespace-mode coming from whitespace.el.

in my init.el I have put:
(require 'whitespace)

I have tried to put after it something like
(whitespace-mode)
or (whitespace-mode t) but it does not work.

I always have to activate whitespace-mode by hand with
 M-x whitespace-mode

I think there is a simple way to do it but I am missing it.
Can someone help me?

Thanks!

Aurélien