setting my posts page

How do I set up blog up exactly like the preview below ?

https://selademo.wordpress.com/

i would like my static page exactly the way it shown and then in my menu , something that links to my actual blog starting from its recent post.

I’ve searched and searched but i can find a forum that can help.

my set up at ‘settings > reading’ is :

Front page : new page ( i made a new page just for that)
Posts page : -select-
(and then ‘new page’ as an option which i obviously don’t want)

and i get this :

I have deleted my ‘hello world’ page but i have made tester blog posts which don’t show up and instead i get ‘page not found’.

am i missing something ? where am i going wrong ?

i hope someone can help