Adding sections between blog posts

I am using Landscape theme v1.0.3 by blank themes.

I would like to put sections between my video posts that are permanent so that I would have my header, then a video post, then a section with some text/picture followed by another video post like what you see here:
https://www.hillsong.com/en/

Is this something that goes inside of the style or function or something else? Where can I get the code or some similar code that would help me get a start on this?

Thanks for you help!