posts layout

I selected the page for the posts/blog listings. But I’m a bit puzzled, the latest one is a brief version at the top, under the header, then the next four are laid out left to right in mini column style, with a greyish background, brief versions with social links beneath and only then are the earlier ones laid out one under the other, also brief versions, with my original page layout design for the ‘pages’ design with the sidebar.

Can I delete the mini column left to right bit instead and have the brief posts laid out one under the other with my sidebar all the way down?