Layout for one category Post

Hello team,

I am learning how to use GP and I am quite lost, the more I read the worst.

I want to create a very simple layout for one post category, but I am lost. So please give me some light here.

I want to create a 2 column layout were the first column 70% presents the featured image and the second column 30% presents the text from the post something like this https://a.cl.ly/eDuBkGvm

I am using GP Premium Version 1.11.0-alpha.2

Thank you very much