Look up and read the word "perseverance" even if you know what it means. Read it 50 times in a 50 day period. Then look up the word "discipline" and then the word "devotion".
An aspiring writer will doubt themselves in one way or another at some point. The weight of writing itself can be cumbersome and a dread of writing may overcome their earnest efforts.
Hence the combination of the three words perseverance, discipline and devotion will help the aspiring author breach through their trepidations.
I myself embraced the discipline of embracing vocabulary words. A hunger to comprehend the vast amount available in the english language. Of course to learn comes easy to retain is quite another thing.
Writing is a craft and in a way an art form. Begin here if you are young and build upon your craft in a way that will help you form your own identity.
Afterwards humble yourself and begin the journey of asking/inquiring about all aspects of writng, publishing and marketing.