First of all, don’t be impressed by that MFA. It was an expensive degree but it is useful. That said, you do not need an MFA or any college degree to become a good writer. But here are some tips if you wish to get your piece in print and possibly turn writing into a side-gig or a full-time profession.
First, understand that writing is both an art and a commodity. You write in your voice but you shape your voice to other people’s expectations. You write for others but you write as yourself. Don’t try to be Gaiman or Martin or McCarthy or Jemison when you write–be yourself.
Second, murder your darlings. This phrase is considered a cliche by some but it holds up. It means “Don’t write a paragraph or a scene around a pithy bit of narrative, exposition, or dialog.” Too many people want to be clever in their writing and fail to understand that being clever won’t impress the reader; what does impress the reader are clarity and conflict (and by conflict I don’t necessarily mean a fight but a selection of choices or conflicts the protagonist finds himself/herself facing.) That impressive bit of snark, moral one-upmanship, or pithy argument? Destroy it–get it out of there–murder it because you think that’s the crux of the scene and in truth it ain’t.
Third, research and write using “scene and sequel” format. A scene is a unit of action; a sequel is a unit of reflection. Each scene leads to choices the protagonist must make and those choices are made during the sequel phase (which then produce the next scene and so on.)
Fourth, get a group of critique partners who will honestly but fairly tell you when your writing stinks. Don’t go to mom & dad or your best friends for honest opinions–they won’t give them to you. Find someone else who writes and get them to critique your writing and brace for the dislike. Good critique partners won’t just hate on your piece but will tell you where they got lost, where the story drags, where character responses are shallow, and what you need to work on in order to improve.
Fifth, after reading a few books on writing, offer to critique the writing of others. This can be done on multiple levels. I am an archetypal or mythic critic: I see parallels between stories and mythology and use mythology to help writers clarify character arcs and use of symbolism; feminist critics help writers create genuinely deep women characters and male characters who interact with women. Other forms of criticism exist and finding your voice as a critic (which doesn’t mean nit-picker or scold) will help you understand who your critique partners should be and what you and they respectively bring to the table.
Sixth, on the subject of feminism, understand that a genuine understanding of feminism produces robust female characters who exist side-by-side with robust male characters. An ugly truth about so-called “feminist literature” written mainly by men is that the women are often forgettable because they are average while the male characters stand out because they are often too stupid to live (too stupid to live = TSTL – this is a thing in writing that should be avoided.) A strong female character isn’t just competent in comparison to every dithering, blathering, weak-willed, impulsive male character; a strong female character keeps the company of other strong women and strong men.
Seventh, show don’t tell except when you need to tell. Telling is done through narration, showing is done through exposition. Learning how to use exposition, narration, and dialog is the trick and this comes with practice and patience. Getting the mix right is what all writers hope they’re doing.
Eighth, take an online class in writing. Without advocating for or against his religious views, the L. Ron Hubbard Writers of the Future contest offers a great online writing course that’s absolutely free. This contest is pretty big and past judges have included writers such as Orson Scott Card. Past winners have included writers such as Patrick Rothfuss. There are definitely other writing courses out there but don’t spend an arm and a leg on them.
Ninth, take a class or a workshop but be prepared to pay for it. If you can find an invite to it or submit a piece that really grabs their attention, the invitation-only Borderland’s Press Writers Boot Camp is an amazing if brutal weekend in Maryland where your writing will be appraised by the likes of F. Paul Wilson, Doug Winter, and Thomas Monteleone. (Hint: If you write horror, you’ll need to mix it up a bit with some fantasy, science fiction, or the like–straight horror is somewhat boring there.) A good writer’s workshop is a great thing to experience.
Tenth, and this is the biggie–Don’t pay to play! Don’t fall for the scam that it takes money to make money in writing. If someone says, “We’ll publish your novel for $2,500” don’t do it. If someone says, “We’ll publish your short story for $25” don’t do it. You’ve invested time and effort into your writing and that’s your cost, not some random publication fee. If you don’t get paid but get a short story in an online magazine, that’s fine–you’re playing for fun. If you get a token payment of $5.00 for a shorty story, that’s fine. If you get pro rates of $0.10 per word, let me know the name of that market because I need to submit there. 
If you pay for a valid critique of your piece, get it, but it doesn’t get published, then that’s acceptable, too. What you never want to do is pay for someone to print your work.
Eleventh, if you do land a piece, read the contract before you sign it. Look up the meanings of the various rights the publisher is buying from you. Check out their website and see what rights they buy from their authors. Also, don’t publish your piece on a blog before shopping it out (if shopping it out is a goal.) Most publishers want “first rights” meaning they want to be the first to publish your piece; if you put your piece up on social media or in a blog and then sell them your story–even if you’ve since deleted it from the other platform–they can and probably will sue you for it.
Twelfth, take all writing advice with a grain of salt. Starting with my own.