I was asked during an interview what advice I would give a new writer who is just starting out on their writing journey.
I have a bunch of advice I'd give someone starting out, but one of the main things I always say is: write the book.
If you don't write the book, you don't have anything to revise. You don't have anything to workshop. You don't have anything to edit. You don't have anything to submit to publishers or agents. You don't have anything to publish. You have no real proof of the quality of your work.
Write. The. Book. Don't worry about whether it's perfect or publication ready. Don't worry about what other people will think of it. Don't even worry about what you think of it. Just write the book. For anything to move forward, you have to have something in hand, something to submit. Write the book.