I came across this post on The Book Designer.com. It contains some really helpful information. Having published four books on Kindle, I’ve seen and received so many questions on how to self-publish a book. It is daunting but not impossible. Articles like this provide much of what you need to know. The process also changes from year to year so even veterans need a little refresher from time to time.
https://www.thebookdesigner.com/2019/09/publishing-your-book-is-changing-on-amazon-kindle/