I understand your volunteer work goal may be to "use a math / CS skill-set to impact my community in a positive way". There are many ways you can use your skill

I understand your volunteer work goal may be to "use a math / CS skill-set to impact my community in a positive way". There are many ways you can use your skills. For example, you could start participating in a well established and valuable open-source project or take a part in hackathons solving big problems, you could organize workshops, teach people. Anything you do, remember to balance your volunteer work with other parts of life and career.