Either I’m the biggest bleeping idiot on the planet or Facebook has the worst bleeping interface of any major software application EVER, bar none. Actually, it occurs to me that the two aren’t mutually exclusive. I’m following other groups so I know I’ve done this. Did the method change?
Oh, I think I stumbled upon it. But of course, how could I have been so stupid? You have to go to the group page and press the “Like” button. This is of course a major design error. “Like” already has a specific meaning. The button should be “Follow” or something. Idiots!
But wait a minute. I want it to be listed under my groups on the news feed also. Oh, Facebook. Anyone?
Btw, I’ve looked on line for answers to both questions and couldn’t find anything. Maybe it’s just me. 
If a page doesn’t sport a “Join Group” button at the top right then it is not a Group it’s a Page. If it has “Like” at the top right then it’s a Page not a Person. If the page has “Add Friend” at the top right then it’s a person not a page or a group.
You’re confusing types of content so that’s why you’re not finding anything in help.
Thank you, ZipperJJ. I think your reply makes my case about the Facebook interface. 