Thanks for replying.
I am already using a child theme where I have started creating custom templates for posts.
I’m just not sure what and where to look for the correct methods to do what I need.
My site is here: https://new.holosuitemedia.com/
You can see there that the square images work when you scroll down.
However, when you go to a post like this: https://new.holosuitemedia.com/podcasts/theexpanse/2020/08/episode2-before-kirk/
The top banner image needs to be rectangular – So I want to be able to set a rectangular featured image to use here, and maybe some social networks like Facebook.
Many thanks, Steve