I am a new to Emacs , i downloaded auto-complete , moved it to ~/.emacs.d/plugins/ then modified the .emacs file to look like : 

```
(add-to-list 'load-path (file-name-as-directory
                     (expand-file-name "~/.emacs.d/plugins/auto-complete"))\
)

(require 'auto-complete)
(global-auto-complete-mode t)

(ac-config-default)
(custom-set-variables
;; custom-set-variables was added by Custom.                                   
;; If you edit it by hand, you could mess it up, so be careful.                
;; Your init file should contain only one such instance.                       
;; If there is more than one, they won't work right.                           
'(menu-bar-mode nil)
'(package-archives (quote (("melpa" . "http://stable.melpa.org/packages/") ("g\
nu" . "http://elpa.gnu.org/packages/")))))
(custom-set-faces
;; custom-set-faces was added by Custom.                                       
;; If you edit it by hand, you could mess it up, so be careful.                
;; Your init file should contain only one such instance.                       
;; If there is more than one, they won't work right.                           
)

```

when i restart emacs , it displays the following error :

```
Warning (initialization): An error occurred while loading `/Users/zeaksilva/.emacs':

File error: Cannot open load file, auto-complete

To ensure normal operation, you should investigate and remove the
cause of the error in your initialization file.  Start Emacs with
the `--debug-init' option to view a complete error backtrace.

```