When it comes to indie publishing, I feel the way to go would be a mix of Youtube Marketing to get attention to your book and the type of writing you do. You can do this by establishing a channel around your books theme, talking about similar books and then gradually working towards mentioning yours. You can also utilize creating landing pages around your book to help bolster sales and utilize free publishing platforms that only charge you when a book sells and covers any kind of overhead of making your own book from scratch or worrying about landing a publisher!
When first starting out though yes, Amazon would be the right way to go until you fully establish yourself in the market as Amazon will get you some exposure naturally that you normally wouldn’t have.