BuddyPress.org

It all depends on what you want to do with your community.

Since you have no experience with WordPress, the BuddyPress for Dummies book might be a good way to start:
https://buddypress.org/2010/03/book-buddypress-for-dummies/

If you have some coding experience, it shouldn’t take you long to get up to speed. Although it would have helped to have some idea of how WordPress works, especially with themes and hooks.