Blog Post Page

Hi

Currently, I'm using the Prime template for my e-commerce and blog website. I want to know how to reduce the blog post-viewing area as I'm going to add right-side widgets.

I have already tried reducing the container width in the customizer. It reduces the width of the entire website which I don't want.

Example: https://www.wpbeginner.com/plugins/how-to-properly-set-up-ecommerce-tracking-in-wordpress/

My Website: https://www.bestmom.in/best-room-heaters-for-baby/

Thanks