How to make the first post full width wordpress?

Question

Layout

There is a standard template with three columns, there is no slider and such a thing at the top of the page. just three columns of posts without sidebars and extras. How can I make the first post full width above all posts, like a slider, only it will just be the first post from the general list of posts. In which wordpress theme file do you need to look in order to make the layout of this first post there?

An example is attached (not real):

Answer 1

create a vp template
and at the top, select one last post, and at the bottom, the last 3. and style and typeset. then do not forget in the settings - read to put the main page not a list of posts, but yours, which you created with a template