About a week ago I noticed that the Related post function that normally appears at the bottom of the “post page” is missing. I’ve also noticed that the suggested tags function is missing too. I’ve tried downloading plugin thingies but I’m totally lost now (can’t even find plugins)
Not sure you knew, but plugins can’t be installed on WordPress.com sites, only on self-hosted WordPress.org sites. The functionality of many popular plugins is included within the features of WordPress.com.