Category and Single Post pages

Could use some help with understanding blog posts/categories. I have developed a site for a pet sitting company. For the blog I have been able to create a slight variation in structure and style to allow for a two column layout with the sidebar. However, when I look at the categories they are single column but I need them to use the same format as the single post. Any advice is greatly appreciated.

Need this:
https://manymutts.com/category/blog

to look like this:
https://manymutts.com/tips-to-get-your-dog-licensed/