You didn't give any link yet, but I guess you mean the advertisements on main pages? You cannot disable it, it's something that you get with FANDOM, as in many other sites. At least you don't get ads on any page, as users get when they are not logged-in.
You have specified neither what is showing up nor where on the page. You may be talking about what HumansCanWinElves mentioned but we have no way of knowing. You could also be talking about the "Popular Pages" section in the right rail, the "Fan Feed" section in the global footer, the ad section in the right rail, or something else we haven't even thought of. Please try to be more specific.