The "c2patool" is a good complimentary tool for inspecting the files created by this tool: https://github.com/contentauth/c2patool.
Technical specifications for C2PA standard assertions including JSON samples: https://c2pa.org/specifications/specifications/1.0/specs/C2PA_Specification.html#_c2pa_standard_assertions.
OWASP Overview of cross-site scripting with links on how to test on the different forms of cross-site scripting: https://owasp.org/www-community/attacks/xss/.
OWASP Testing Guide section on SQL Injection: https://owasp.org/www-project-web-security-testing-guide/stable/4-Web_Application_Security_Testing/07-Input_Validation_Testing/05-Testing_for_SQL_Injection.
The4 PayloadBox GitHub Repo has a collection of injection strings: https://github.com/payloadbox.
For sample file types beyond JPEGs for testing, the C2PA maintains a list of sample files here: https://github.com/c2pa-org/public-testfiles.
If you want to create your own certificate authority, see the scripts in https://github.com/c2pa-org/testing-private/blob/main/cert-generation/.
Rather than generating your own certificates, you can also test creating your own manifests using provided pre-built certificates; see Creating and using an X.509 certificate for more information.