Welcome to the community @deebolland!
Text columns are actually a more recent addition than the column element which has been a part of the Designer since just about the beginning (as far as I recall) and more depreciated than their text counterpart. With the addition of CSS Grid and Flexbox, you can accomplish much more complex layouts that are more versatile and I’d encourage using either over the default column element.
To find the text columns option, just open up the “More type options” toggle under the Typography section in the Style panel:
If you apply columns to a parent element containing two text elements (like a heading and paragraph) you can have the heading span across the columns by selecting it, clicking the three dots next to “Columns” and choosing “Do” under the column Column Child span option:
This will stretch the element so it doesn’t flow within the normal column layout:
