How can I make this image the background

Hi, I’m trying to make the image on the front page a background image for that section. Please help. Here is the Code Pen link

First delete the img tag from your HTML Markup.
Then add this Rule to your stylesheet. You can change the body selector to your desired section class or id.

body {
     background: url(http://stockpictures.io/wp-content/forum/uploads/2016/05/macbook-laptop-books-desk-wood-notepad-pencil-eraser-drawing-iphone-textbooks-768x515.jpg);
     background-repeat: no-repeat;
     background-position: center;
     background-attachment: scroll;
   }

You can play around with the image properties like repeat, position, attachement etc.
This is a low resolution image, you should choose an image with a resolution of at least 2k.

Thank you so much! Really appreciate you taking the time to help