two columns of twenty twelve POSTS?

Do you have a child theme set up – that’s the first step – so that your modifications won’t be overwritten when WP is updated.

https://codex.www.ads-software.com/Child_Themes

I do

See: https://www.transformationpowertools.com/wordpress/posts-in-two-columns-twenty-twelve

Ok. I have 2 questions:

do I add the filter function at the very beginning of the functions.php file or somewhere within the existing code?

also: the minimum css code — where do I put that? in the style.css file? where if so?

thank u

p.s. i understand that any of the changes are made in the child theme versions of each file.

Use the Child Theme functions.php file which is NOT a copy of the parent theme functions.php file – read the link above about Child Themes if you are confused.

The CSS code goes in the child theme style.css file – which should only have changes to the parent CSS in it.

What’s your site URL?

Okay, thank you. I’m developing it here: https://internalcompass.us/castle/