How to set line wrap

[RAYHAN MUKTADER]

Hello,

Could some tell me how I can set the line wrap to 80 characters?

The following is what my ~/.emacs file currently looks like:

(set-fill-column 5)
;; Turn on tabs
(setq indent-tabs-mode t)
(setq-default indent-tabs-mode t)

;; Bind the TAB key
(global-set-key (kbd "TAB") 'self-insert-command)

;; Set the tab width
(setq default-tab-width 4)
(setq tab-width 4)
(setq c-basic-indent 4)
(load-library "php-mode")
(global-font-lock-mode t)

As you can see I have set fill column to 5 just to test it.
However,  My my cursor does not move to the next line after I go pass
five characters and I don't see any change in highlighting either.

I have also tried C-u 5 C-x f  but I did not see any difference.
Kindly help.