If you ever thought about contributing to Vanilla, then this is the best time for it: it's Hacktoberfest!
Each year DigitalOcean announces the Hacktoberfest. Everyone who makes four qualified pull requests to any project on GitHub between October the first and the 31st will get a shirt.
So you think that is only for developers? Nope. If you find a typo anywhere, create a pull request! Start by creating a GitHub account and register on DigitalOcean
Afterwards go through the Vanilla repos and see how you can help. Well, you certainly can contribute to any project you like, but if you invest time, why not doing it for your favorite forum script?