After you create a new Leanpub book, you can put the book in "Stealth Mode". You will see this option in Admin section of the book's menu on Leanpub.
When a book is in Stealth Mode, information about the book is not made public.
You can then use Leanpub to generate ebook files that you can download and then distribute using any distribution process you like.
Leanpub only makes ebooks. However, we have a "Print-Ready PDF" option that lets you generate a PDF you upload to print on-demand services like those provided by Lulu or Amazon. Then, you can pay them to make printed copies they can send to you for distribution.