How do I load pages in 2 columns?

I’ve scoured the Internet trying to find people having similar problems to mine so I can kind of Frankenstein a solution, but that’s not working this time. What I want to do is this:

https://frsh.pw-software.com/frsh+blog.png

I figured out how to split my recent blog posts into 2 columns, as shown. What I *want* to do is, when someone clicks/taps on “Older posts”, I will get my next page of posts (which would load the next 12). The left side obviously has the latest 6 posts, while the right side as the 6 after that. Here is my code, thus far:

[Code moderated as per the Forum Rules. Please use the pastebin]

I have seen people with similar problems use “explode” and things like that, but I do not understand any of that, lol. Does anyone have ideas as to how I can figure out this puzzle?

EDIT: This article seems to have something close to what I want to do, under “Breaking Categories into Columns”.