featured image size post in blogsummary

Hey,
In Theme Options > Blog Options you can set the Standard Blog Post Summary Default to Landscape Image.
I would recommend using a plugin like Yoast for setting sharing images, excerpts, etc. https://www.ads-software.com/plugins/wordpress-seo/

Hannah

Thank you Hannah, what size do you recommend?

It’s really up to you and the look you want. You don’t want to go too big because large images will slow down your site. But too small of images will look distorted. Typically something like 1200×800 is a good place to start. Take a look at this post- https://www.kadencethemes.com/background-image-sizing/

Hannah