There are hard and fast rules for English literature. I break them all. I'm not the first. Mark Twain was one of the first. There is only one piece of advice I can give you. Write from your heart and soul and make it your story, not the story some professor or teacher taught you.
For your other part of the question. Their rules here are pretty relaxed. Their main one is "play nice" and keep your insults if you don't like a post to yourself. Most have never learned the "ART" of constructive criticism. Instead of dissecting the story, they shred the author.
IF..., you are writing TG you do not need the boy-girl blender in every chapter. One telling in the story is enough to qualify as TG. Some here will have different opinions on how the transition should affect the character. They want the whole female periods, awakening and exploration of the inner instead of the outer along with all erotica. If that is your thing then tell your story the way you want. If it isn't then tell your story the way you want.

Got the picture now? It is your story. Crawl inside it with your characters and tell it as you and them live through it. When it comes alive for you it will come alive for everyone else who reads it.

If English isn't your first language find a proof reader. I noticed several grammatical mistakes in your story. Nothing serious and didn't distract from the telling. They are minor speed bumps when we hit them. Have to stop reading, back up, analyze the sentence or paragraph, correct the mistake and take off reading again.

Your descriptive mixed in with dialog is in my humble opinion spot on. You set the scene or stage, have the actors come on and do their speaking parts. Very, very well done.