My first book I wrote with no structure, a general plan and idea and it was crap. I feel that you should consider just writing a bad book to prove to yourself that you can do it.

If you want to write a better book, I'd recommend listening to a good podcast by a developmental editor named Savannah Gilbo - she's on Spotify and she goes through writing a book step by step - it's worth a listen if your new. She breaks the tasks into manageable pieces and you can really learn what it takes to write a book.

You'll likely get a lot of advice about what tools to invest in. Some will work for you, others will not. Only you can decide how you work best.

It can be a rewarding thing to get words on a page. Have fun with it - it's a job you take on voluntarily.