For anyone who's new to this site, here's how to add categories on any page correctly.
There are four options to add categories:
Contents
Option 1. Actual Page
First click Add Category on the bottom of the page, then type in the category, which will bring down a list to find the category you want to add. Click on the category to select it. Then click Save, and it's added to the page.
Option 2. Editor
This is for the Classic Editor. First click Edit to enter the Classic Editor, then type in the category, which will bring down a list to find the category you want to add. Click on the category to select it. Then click Publish, and it's added to the page.
Option 3. Visual Editor
Note: The category list is pretty bright and hard to see, this is only for those that can see well on bright text.
Click the arrow next to Edit and click VisualEditor, then click the list to find Categories and click it to go there. type in the category to bring down the list to select the category you want, Click on the category to select it. Then click Apply Changes, and click Save page.
Option 4. Source Editor
Note: It doesn't show the list of categories to add, so you have to type it in instead which makes it hard to remember what category you're adding.
Classic Editor
Go to Edit, click Source, type in the category at the very bottom. And click Publish.
New Editor
Click the arrow next to Edit and click VisualEditor, then click the list to find Source Editor and click it to go there, type in the category at the very bottom. Click Apply changes, then click Save page
