Adding Columns & Sections
If you either want or, need, to add some columns to your pages in Confluence, there's good news: it's easy to do!
The control for adding sections to a page is this one:
It's called the Page Layout button and, when you click on it, you get a toolbar that offers you all of the options you're likely to need.
Clicking the left-most selection, 'Add section', does exactly that. It adds a section to your page that you can populate with text, images, tables and all manner of other content. Mind you, if you have already put content onto your page, that will become the first section. You can, dynamically, add more content to the section so that the section stretches vertically. However, there is no resizing capability for the horizontal dimension.
When you add a section, it will extend the entire width of the page. Only when you choose any of the columnar options to the right of the toolbar will you see columns that have varying widths that are less than that of the page.
Choosing the second option, 'Remove section' comes with a caveat: if you already have created a section around content that you have put onto the page, choosing to remove the section will also wipe out your content!! If you do this and you need to get your content back, use CTRL-z (Undo) immediately. Doing so will retrieve your content. However, you will still have everything in a section. If you are still determined to remove the section, highlight the content within the section, choose 'Copy' from the formatting toolbar–or, use CTRL-c from the keyboard. Then, click 'Remove section' and paste your content back onto the page sans section (you can use CTRL-v to paste, too).
'Move up' and 'Move down' perform exactly as advertised: if you have a section that you have added to a page, these two choices will move the section up or down on the page so that you can place it in the precise location you determine it should go.
The next series of icons may, or may not, seem a bit obtuse. Nonetheless, they are there to help you put your content into columns. All of these options work from the premise that you have already added a section to the page. The first represents the default case: a single column section. Where you might make use of this is when you have formatted a section on your page with columns and have determined that your content would be better served in one section/column on the page.
The second selection is for a two-column section. By clicking that, you will see two individual sections appear on the page.
Here again, realize that if you already have content on the page, choosing this option will put all of your existing content into one of the columns.
The third option is 'Two column section with a left side-bar'. This forms a wider section to the right. Similarly, the next button to the right is the 'Two column section with a right side-bar' and yields a wider section to the left.
The next icon to the right is for a three-column section. Each column with be identically sized.
The last button is 'Three column section with side-bars'. Here, the center column is the widest.
The best suggestion we can offer is that you try them, if you're either curious or, of the mind to use what they can provide by way of page formatting. See which of the options works best for your purposes and aesthetics. Just remember: you can always undo....!