Another great way is to check out the BUILD.md file to see how you can build it, run it, test it, etc.
Contributions, small and large, are welcome. Minor contributions and bug fixes are always welcome in form of pull requests. For larger work, the best is to check in with the existing developers to see where help is most needed and to make sure your solution is compatible with the general philosophy of Voltha. Please check out the contributing page on the documentation.