please i am new to cms and i realy must know how to apply them to my web pages to make them easily updatable

Choice of CMS depends on the kind of functions that you desire your website to have. What kind of website are you building?

its a simple church website , where a dummy can easily update a page without knowing html, all he needs to do is edit and click on submit and the changes take effect. or is there anything on your control panel that can do that?

Joomla would not be a bad idea for what you have in mind. You can easily install it from your cpanel Script Library, Installatron.