I was asked a very long time ago to post some advice about writing for beginning authors.
This is more difficult than it sounds.
Writing is... Okay, I'm not going to say it's a mystical experience that can't be pinned down, or that it's something one does and cannot be taught. But it is difficult to describe.
If you're cooking, the implements involved are standardized: measuring cups, a specified size of baking pan, etc. Writing is all in the brain, and everyone's brain is different.
For example, say I give you an egg and say, "Open this." You might opt for the edge of a bowl, a hammer, or a Rube Goldberg machine (Heath Robinson, if you're in the UK) which involves several dominoes, a whisk, and a cat. All would be equally correct in writing. It's your creation. You do what you want.
So much freedom can leave you paralyzed, wondering what to do first. I can help with that.
First, decide how you want to write.
Back in the day, this wasn't a problem. Paper and quill. That's it. Even with the invention of typewriters, it was still generally found to be easier to write out one's story with pen and paper, then just type the final draft.
Computers changed that.
Yes, it is easier to type and format on a computer. You can also get so caught up in the minutiae of word processing that you edit and re-edit the same damn paragraph instead of going on to the next chapter. Or you can stare at the white abyss of blank page while the horror of nothingness stares back at you. So then you go surf the web, tweet some folks, and check your email five times.
So my first bit of advice is: Decide if you are a pen-and-paper creator or a computer creator. Which technique will make you more productive? Because that's what it's all about, producing the words. What separates authors from wannabes is actually finishing the book.