Self-publishing with Amazon KDP (Kindle Direct Publishing) is free and relatively easy. They have helpful information and tools available. Using their cover creator allows you to make a decent cover, and you can upload your own images for the cover. The resulting printed product generally looks good. Also, they make it easy to view sales and royalties.
A downside to publishing with Amazon that is perhaps little talked about is that some bookstores will not accept books on consignment that are printed by Amazon. It is viewed as a behemoth that cuts into their business by offering lowered prices.
Another reason might be that bookstores want to order books from distributors like Ingram that are returnable if they do not sell.
Amazon does provide an Expanded Distribution option. They will list books with the distributors so that authors might reach more readers in bookstores, libraries, and online retailers. However, if one chooses this option, the royalty rate will be less, and Amazon does not guarantee a book will be accepted by distributors or ordered by a particular bookstore or library.