Don't worry. If .emacs doesn't exist, visit it in the default directory and it will be created automatically. (If you know how to set an environment variable, you could mock GNU and Unix setting HOME to /home/username.)

To change the default colors, you could append something like this to your .emacs:

(when window-system
  (add-to-list 'default-frame-alist '(background-color . "black"))
  (add-to-list 'default-frame-alist '(foreground-color . "cyan"))
  (add-to-list 'default-frame-alist '(cursor-color . "yellow")))

Next time you have a question about Emacs usage, please search www.emacswiki.org, or else post your question in http://mail.gnu.org/mailman/listinfo/help-gnu-emacs.

This mailing list is meant for reporting bugs in GNU Emacs.