Conflict between Cover Page and Customizer

Hi,
I’m very new to WP and GeneratePress, so I’m sure this is very obvious. I am using Dispatch, which is clearly out of my league. I see how to use WP Show Posts on specific pages, and the Customizer is affecting (tweaking elements) of the home and parts of other pages.
I want to modify the middle section of the Home page and put in the results of a ShowPost, just show 4 of the latest posts. Should be simply using a shortcode and put it on the Cover Page file, like any other page.
But I see shortcodes came with it, were already there (doing what I want!!) and it seems like the Customizer is overruling what’s being called for in the Cover Page and int he Show Posts. Is the Cover Page where I should be working?

At the moment, I’m seeing only a list of my posts on the home page. They are styled beautifully but I want to group them into segments by topic. I thought putting shortcodes on the Cover Page would do it. Any suggestions? I’m sure I have a mistaken concept in here somewhere.
Thank you.

The page I need help with: [log in to see the link]