Problems with theme setup

I cant not find out how to change what I see when I click on a menu item the page that loads has what might be some big slider on it followed by 3 posts lined up in squares then 2 posts below it. How do I remove the slider, or have any choice even on what loads on when I click my menu item

My site is hidden because it is now such a mess so I cant give url as you wont see anything.

Wish I could upload an image here.

I have discovered that the page I see when I click my menu is my category page as my menu items are my categories.

So under the theme editor I can set how the posts show on this page. The problem is at the top is still this massive area with one small image in it which appears to be pulled from the first post, it looks terrible.

When I select which module to show no matter which one I choose this image appears. I need it removed as it looks terrible at the moment.