What should I learn first React or React Native?

Definitely . The experience in creating applications using native technologies can for example help in application distribution or working with mobile devices in general. However, creating both the user interface and business code in JavaScript may require a slight change of mindset.

Yes, it is advised to learn React before you start with React Native, since the principles you’ll need when developing in React Native are all based on React.8 Nis 2016

Learning React Native when you know react already is easy enough . The difficult parts are largely the same. Styling and UI/UX is pretty different for mobile apps so that takes some getting used to. But if you know React well you won’t need more than a couple of days to transition to react native.