Which license should I use?

We cannot advise on what would be the appropriate license for each use case. Licensing of materials heavily depends on your affiliated institution/organization's policies, or e.g. when publishing supplementary materials for journal articles on the publisher's policy. I would suggest that you either ask your institution's library, your project manager (if this work is part of a funded project), or contact the publisher for more information to find the most suitable solution for your specific case.

Generally, we can recommend for software using GitHub's license selection tool, and for everything else the Creative Commons license chooser.