Autofocus side button

I want to add a default side image to my posts in Autofocus

I have changed the format so that all the posts are just one row. Ultimately I want to add a button (which will just be an image with a link) to left side of each post. This button won’t change so I just want it permanently at the left side of all posts.

This button will open a link that is placed within the post, so I don’t just want the button to be separate from the post (such as making a side bar and moving it next to the posts on the leftside). I know this is a whole other task, so I will concentrate now on just getting a side button for each post (keeping in mind that I eventually want to be able to connect the button and post link)

I was thinking about adding an extra div container in the home.php file ( would this mean that I would have to go to the style.css file and add some code to make styling easier?), but I’m not exactly sure. Any help would be appreciated!