I am excited by the idea of contributing to cryptocurrency projects. Many of these projects have their code stored on GitHub. I have published previously blog posts on How To Set Up GitHub In 20 Minutes and A Complete GitHub Tutorial.
If you have watched these tutorials, you should be ready to contribute to a cryptocurrency project. This video explains how forks and pull requests, the keys to be effective in GitHub and Git, work. If you master the ideas in this video, you will have the knowledge to help out your favorite projects.
Best wishes for success! Ira