Simply put you can't. For starters CQ5 is a modular CMS in that you drag in various components to build a page up. You have page templates that contain the basics of a page such as the header and footer but you don't create entire pages in one go so to speak. You build them up from reusable components.
Second you can't automatically convert an illustrator file to a webpage, you need a web developer to translate it into HTML, Javascript, JSP's and CSS. Also CQ5 can require quite a bit of back end coding in Java so that is something to keep in mind.
CQ5 is really an enterprise CMS so depending on your needs it might be worth taking a look at something like Wordpress although you still wont be able to simply upload an AI file.