In this article I am explaining the codes in details way. So you can easily create a grid layout for your posts listing page on your site.
Creating a new template file “page_fw_3cols_blog.php”, adding some custom PHP codes and putting the file in child theme’s folder. Here is the complete code of this file:
Adding the CSS for style. Open your style.css file and add these CSS there.
Now login to Dashboard and create a new page (Pages -> Add New). Select the “Full Width 3 Columns Blog Page” template from Page Attributes -> Templates drop down list. Hit on “Publish” button and live the page. Now click on “view page” link and see the output.
If you need any help then you can feel free contact me.