grid around div/img


I’m using Pinbin to make a website. I want to have a grid of posts form around an image (to the right and below, as the image is left-top). I have the image placed in the index.php and the grid from Pinbin, but it doesn’t form around the image as you can see:

How do i make it work? If you need more info please let me know. I’m a beginner in building websites…
Thank you!