How do I edit the “posts” template?

I feel like I should be able to make some rudimentary edits to the Blog / Posts template using the Page Builder.

On my front page, the posts will be one column, but I still need to edit the layout of the page that specifically displays every blog post.

I’ve tried and tried and all I get is the blank page inside the old editor view, with the text “You are currently editing the page that shows your latest posts.”.

I’ve spent over an hour trying to google this, but when “template” means both page-template and site-template, the google results are unuseable.

I’m starting to fear that I won’t get any further without buying a different template, or hacking with injected CSS code, and if that is the case, it would be good to know.

Beyond that, any pointers on how to edit or modify this would be much appreciated.

I’m quite surprised that the page builder isn’t just “there” when I open it through pages, wonder if something may be broken, as well.

I can’t find any documentation from WordPress about the area of Themes beyond their installation. Even their own themes. Grumble grumble grumble.

Hope that someone knows something!

Sv.