If you want to publish a book, you can do it for free with Create Space, https://www.createspace.com
There are lots of self-publishing venues. They offer different things with different royalties, advantages and disadvantages. You can research this further. You'll find reviews and comparisons on the Internet as well as written up in varies books. You can decide what works best for you.
Create Space is fantastic because you spend zero money up front. Create Space is owned by Amazon. When your book is sold, at that point Create Space gets a percentage and you get a percentage.