Schools are expensive, best to get it when it is free, but that's the old story, if I only knew then what I know now. I find occasional glances into books can be more confusing than helpful.
I have learned that not having a useful educational experience for writing is not a good idea except for writing free form poetry where you can make up your own rules. It is much harder to get people to read your writing the more off mainstream you go.
There are two aspects to writing, the mechanics, and the style. The mechanics never goes out of style and if you are a good mechanic you can always got a job correcting other people's writing, in almost any field of interest. There are far more bad writers than good writers and good writing is needed at any level of business to get things done in a reasonable manner. The style is a completely different issue, but I would think if the mechanics are good, and the story is good, you get more leeway on the style of your writing. The good mechanics will keep you from a writing style that tends to leave readers in the dust. Getting a reader confused when reading a story is the best way to get them to put the book down, in more ways than one.
Feedback from readers is very important for me. It makes up for missteps that have been written into the text. Listening to what people say about what they felt about my writing gives me the best chance of staying on track as far as writing something people might want to read. I may not change it the way they want it, but I will try to make things make more sense.
The good thing about self publishing is that if want get your work published under any circumstances you can do it. Learning how to do that is a lot easier than it seems and should not be an obstacle to getting your work published. I would recommend using word (or a program that offers warnings and or corrections), a thesaurus, a dictionary, and checking on line to see what which word might be a better choice, I like to search by asking, better vs good, and see what comes up. You can learn something every time you look. Another thing I like to do is check to see how many times I use the same word, sometimes I find myself using the same word way too many times because it sounds good to me when I read out loud what I have written to see how it sounds. Repetition might be good for music lyrics but is usually bad for story writing.
Writing circles can be good or bad as you find out that some people will claim that what worked for them is how everything should be done. Many indie editors will give your work the same slant they give their work which may or may not be a good idea. You might also find that your social and political views are too important to other people to let them be able to see what you are writing, regardless of the socio political content.
Reading what other people have written is up to one's personal preferences, at any rate, it lets you see what other people are doing. Reading material that is relevant to what one is writing is never a bad idea.