Now the guide works just fine when I do M-x eval-buffer for my "~/.emacs.d/init.el" file. However, as soon as I restart Emacs, the changes are gone. I have to eval-buffer every time I start emacs. I also checked some websites which explains me to have either .emacs file or init.el file and not both. But every time I delete my .emacs file, Emacs generates it automatically when I restart it.
What am I doing wrong?