Blog Roll doesn t show summary,only full post.

I m testing the blog page…it s not live yet (shown on the main Menu)
https://www.patapiatzotzoli.com/blog/

The blog page shows the full article. Tried to change the settings on “Reading” to summary but doesn t work.
Also in the attributes of the blog page there is not a selection of a blog template….
So how can i make the blog page showing a summary of the post and not all the post? I would like to have also…”Read More” and then click to see the full post.