It is a perverse corollary of the 80/20 Rule: Early on in your career at least 80% of your writing will be utter crap. If you're lucky, some of this crap may be improved by extensive editing. But most of it will be irredeemable, irrevocable crap.
Many new writers get deeply discouraged when they first discover this horrible writing truism. But we all have no choice but to face up to it. And the sooner, the better.
When this truth starts to sink in for you, be ready. Don't resist. It may not feel like it now, but it will take you one giant step closer to becoming a good writer.
And it will free you from much of the self-imposed pressure you'll face during your early months and years as a writer. If most everything you write is going to be crap anyway, why not take chances, stretch yourself and have some fun?