But here's the first fact (not opinion: fact) to keep in mind. The person who creates it gets to make the decisions. That's the law. If I write a story, I get to decide who distributes it and how. I can give it away. I can sell the right to, for instance, publish it in North America...but not anywhere else. I can sell all rights. I can sell the right exclusively for a term of months or years (and then re-sell it as a reprint to someone else) or for longer terms (as long as it's in print, defined by me and the other party.) I get to make these decisions because, at root, it's MY story, because I created it. That is the legal foundation on which copyright law rests.
Hold that thought. My story, my decisions. Your story, your decisions. His/her/their story, his/her/their decisions.
It does not matter whether the story/poem/novel is published or unpublished (though published work is a easier to prove infringement on.) The story you just wrote down, by hand, in a old spiral-bound notebook....or typed on the back spoiled photocopies of something else.....that story is your story and you have ownership rights in it. You have copyright--the right to decide who can copy and distribute it.
Second fact: you have copyright only in your own work. You have NO copyright in my work, or her work, or his work...only your own work. You can't legally make decisions about my work or his work or her work--only about your own work. You don't own it, any more than you own someone else's clothes, dishes, pets, etc. If you copy, distribute, anything someone else wrote, without their permission, you are infringing copyright. That includes: letters, emails, essays, short stories, poems, all the way up to multi-volume works. It does not matter whether or not you make money by such copying and distribution--giving away someone else's work, without their permission, is infringement. It is illegal, just as giving away their underwear or their forks or their dog would be.
So hold these thoughts: if you create it, you own it and you get to make the decisions. And if you did not create it, you don't own it and you don't get to make the decisions.
More to follow, because it's very important and I've recently had to deal with two different kinds of copyright infringement, both of them damaging to me in different ways.