how to remove the whitelines on my wordpress site

I did some changes to the background on the site and am seeing all these white blocks. How do i go about removing these white blocks.


This site will teach you how to build a WordPress website for beginners. We will cover everything from installing WordPress to adding pages, posts, and images to your site. You will learn how to customize your site with themes and plugins, as well as how to market your site online.

Buy WordPress Transfer