https://creativecommons.org/share-your-work/cclicenses/

You probably want the SA (share-alike) or NC-SA (non-commercial share-alike) but take a look and decide what suits you best.

From https://creativecommons.org/faq/#do-i-have-to-provide-my-name-can-i-ask-that-my-name-be-removed :

Do I have to provide my name? Can I ask that my name be removed?

As a licensor, you may choose to receive under any name that you wish, such as a pseudonym or pen name, or you may choose not to be credited by name at all, and to publish anonymously. You do not have to be credited under your legal name. Most jurisdictions permit this, but you should check to be sure this is valid in your jurisdiction.

If you write something, you own the copyright, period. There’s no registration process or anything like that. If you made it, it’s yours, legally. And the only process involved to exercise your legal rights would just be proving that you’re actually the one who made it.

Of course, none of that makes it certain that no one will claim it as their own or use it for something you don’t want. As a general rule, just assume that anything you don’t want used in a way you don’t like simply shouldn’t be put out into the public at all, regardless of what kind of license you package with it. If you’re an average person and not a billionaire good luck exercising any kind of legal rights for intangible stuff like written words.

It is generally a good idea to include with anything you put out there some kind of license, which could be as simple as a .txt file that says “Made by [name], free to use for xyz purposes with abc caveats”

For a book stuff like that can go into the first or last couple pages that usually include all sorts of random boring information and publisher credits and whatnot

Personally I would keep it proprietary unit I’ve made all the money I can they change it to an open license like Creative Commons Share-A-like