Sure, what do you want to do? What are your interests and skills?
Some example of contributing to Manjaro:
- support. Help others in the forum with their technical problems and write tutorials
- translation. Help translating Manjaro applications to other languages
- development. Develop and patch applications for Manjaro
- art. Create and share art for Manjaro (wallpapers, themes, etc)
- testing. Test stuff and submit bug reports and feature requests
- maintenance. Spin your own community edition or contribute to one of the existing ones. Bug reports and pull requests official editions are also invaluable
- documentation. Help updating and maintaining the wiki.
These are the typical low barrier roles. With longer shared history, other positions of responsibility include:
- moderator. Keeping the forums civil and organized.
- packager. Keeping Manjaro repositories up to date. If you are interested in this, the best way to get started is to maintain AUR packages and send pull requests to Manjaro PKGBUILDs
If you know what you are are interested in doing, I can point you to a right direction.