The article info, such as author, creation date, views etc, by default is displayed below each other.

Setting a background image for your div is easy.

In order to have your image scale correctly on all viewports, you have to do the following. 

To style images that you use in your articles, and not elsewhere, you can easily add some CSS to your template CSS options.

In order to create a box shadow on certain elements you can use CSS. This tutorial explains how you can create a neat shadow for your boxes.

To apply a color to a single menu item, first get the ID or the menu item.