I am new to technology and I have never commented before. This strange form of discrimination seems a little unfair for those of us who don't spend their lives glued to social media. Please help a newbie. How do I raise my "whatever it is" score?
The way the Stack Exchange (SE) system (that Literature, this website, is a part of) works, commenting on other people's posts is a privilege, awarded when a user reaches 50 reputation points. One of the reasons for this is keeping the comments constructive: SE is by no means a social media, and reputation is at least partly intended to be a measure of a user's familiarity with the system.
Comments are intended for asking for clarifications on questions and giving constructive feedback on answers - those two are the main features of the SE system, around which everything else resolves. Comments are supposed to be temporary and certainly not chatty. Note that a user can leave comments on own posts regardless of their reputation score.
A chattier and more social part of the SE network is chat - one only needs 15 reputation points to join it.
As to raising your reputation score, there are basically two ways: asking questions and posting answers. An upvote on a question will bring you 5 points, an upvote on an answer will bring you 10 points. A few good questions or answers will quickly allow you to comment on any post.