My profile says I'm following 124 users and 140 users are following me.
1) How do you even follow another user?
2) What does it mean to follow another user?
3) What, if any, personal control do I have regarding followers and following others?
You can follow/unfollow users.
Click on their name in your friend list to bring up their profile
Click the 3 dots in top right corner
ios should be quite similar (I don't allow Apple devices in my house, so can't speak to their functionality)