https://prnt.sc/mxByOWHRaDT1

how to do it from scratch?

And if we talk about content inside Text addon (Feature addon) you can use > https://developer.mozilla.org/en-US/docs/Web/CSS/columns

<p id="example" style="columns: 2;">
      London. Michaelmas term lately over, and the Lord Chancellor sitting in Lincoln's Inn Hall. Implacable November
      weather. As much mud in the streets as if the waters had but newly retired from the face of the earth, and it
      would not be wonderful to meet a Megalosaurus, forty feet long or so, waddling like an elephantine lizard up
      Holborn Hill.
    </p>

plus

JCE Editor 2.9.63 has built-in feature for that.

Or classic html with bootstrap classes for two columns.

FILE (download, unzip, import)

marek-l.zip