I got made fun of as a child by a parent for doing art and just... never did any ever afterwards. I primarily hang around artists tho and would like to relate to them more, but none of them do creative writing. I've read numerous grammar books, so that won't be a problem, but none really go in to how to construct a sentence, paragraph, page, chapter, plot, etc. I'll happily take any advice on the subject, really anything you can think for someone with actually zero experience.
Good advice I've gotten so far is to just write basically whatever. Also, people who are visual artists and creative writers, which was "easier" for you to become fluent?
I saw a comment recommending On Writing by Stephen King, and another comment seconding it, so I'm gonna third it. Just... keep well away from Stephen King's pokitical opinions unless you're looking for content for shit liberals say or something.
Keep the advice you like, and ignore any that you don't like. Build your own style.
Also, I recommend reading a bunch if you don't already. Shakespeare's stuff is hundreds of years old, but he's still a masterclass on breaking the rules effectively. Hemingway is also good. The way he controls the pace of your reading with his sentence lengths. Cormac McCarthy is also a good one for exploring writing styles, because of how much he can vary in style between books.
You can shortcut all of that by reading articles about those writers' writing styles, but I strongly believe that you can emulate (and learn) styles that you admire just by reading them a lot, the same way we pick up accents by surrounding ourselves with speakers of those accents. The aspects of those styles that resonate with you will stick, and you'll gradually discover your own 'voice'.
Any specific hemmingway novel? I've only read Old Man and the fish
My personal favourite is A Farewell To Arms. But I think you can see emough of his writing from Old Man and the Sea. The way his sentence lengths are very deliberately varied, his carefulness about how much or how little description detail to give. Stuff like that. Grab any two sections of the same work that have different feels - mood, pace, etc - and you can see how his writing style differs between them to help convey that difference.