How to accomplish equivalent of Vim's Ctrl-n in GNU Emacs

(global-set-key (kbd "M-/") 'hippie-expand)

;; Allow tab to autocomplete

 (defun indent-or-expand (arg)
   "Either indent according to mode, or expand the word preceding point."
   (interactive "*P")
   (if (and
        (or (bobp)      (= ?w (char-syntax (char-before))))
        (or (eobp) (not (= ?w (char-syntax (char-after))))))
       (dabbrev-expand arg)
     (tab-to-tab-stop)))

 (defun my-tab-fix ()
   (local-set-key [tab] 'indent-or-expand))

 (add-hook 'as-mode-hook         'my-tab-fix)
 (add-hook 'java-mode-hook       'my-tab-fix)
 (add-hook 'c-mode-hook          'my-tab-fix)
 (add-hook 'sh-mode-hook         'my-tab-fix)
 (add-hook 'emacs-lisp-mode-hook 'my-tab-fix)