I kept a journal in those days too. One which I maintain until life got so hectic I stopped writing personally for awhile. All of the work was training for the writer of the future. During that time I was experimenting with language and formats. The one thing I didn't do but should have was read a lot too.
Read for a writer is as important as writing because by reading you learn from others. You see how the masters of your craft handled a certain scene, what description they used, what dialogue, if any, helped to convey their intent.
For the longest time I read as little as possible. I suppose that's because I was busy with school. I purchased books but I didn't read them. That came later.
Then came college and graduate school and I learned much about putting together nouns and verbs and adjectives. About varying sentence structure and paragraph development and thesis. These are the basics of expository writing -- essay writing -- that is the cornerstone of freshman English. At that time, it is a good idea to practice the principles in Elements of Style because ultimately it will reward you later. Here again I was a late believer because even though I had an interest in writing I wasn't sure I would do it professionally.
Later in college I studied poetry writing and fiction writing. And then in graduate school technical writing. My goal here was to understand the similarities and differences among all these forms of written communication. It took a lot of time after that to sort it all out in my head. I had to burn out and retrain myself to do it (don't do that at home -- remember, I'm a professional ;) )
The retraining period was practically brutal because I was expected to put words on the page (or the screen) even though nothing came to me. What saved me? Reading books. First I read books on writing. That got me thinking. Then I read non-fiction for a bit, histories mostly, and then fiction.
And I'm still doing all these things and writing too to keep my skills sharp and ready for action. So if anyone out there is interested in becoming a writer, you better be prepared to read a lot and write a lot and check your ego at the door. Comments you will receive are on the writing, not on you.