React Native is worked on full-time by Facebook's product infrastructure engineering team. But there are far more people in the community who make key contributions and fix things. So if you need help with your React Native app, the right place to go depends on the type of help that you need.
Many members of the community use Stack Overflow to ask questions. Read through the existing questions tagged with react-native or ask your own!
For longer-form conversations about React Native, we’ve set up a discussion forum at discuss.reactjs.org. This forum is a great place for discussion about best practices and application architecture as well as the future of React Native. If you have an answerable code-level question, please post it to Stack Overflow instead.
If you need an answer right away, check out the Reactiflux Discord community. There are usually a number of React Native experts there who can help out or point you to somewhere you might want to look.
For the latest news about React Native, follow @reactnative on Twitter.