Adding tags to the post

Just to be in “style” ??
Check the “tagging” tag… https://www.ads-software.com/tags/tagging

I looked at what was available, and thought Ultimate Tag Warrior looked best. Actually, it seems to be one of the most ambitious WP plugins overall: https://www.neato.co.nz/ultimate-tag-warrior/

It takes a bit of tinkering to get it up and running, but there’s a pretty good official forum if you get stuck. And if use Widgets, you can find a couple that display tag clouds and related posts on your sidebar here: https://widgets.wordpress.com/