I don't recommend learning Redux the first weekend you learn React. This would be akin to learning about Relativity the first weekend you learn Mechanics. I actually think it's detrimental to suggest beginners learn Redux alongside React because it unnecessarily steepens the learning curve.
Not that Redux is too complicated (it actually has a super simple API). Redux is a (fantastic!) tool you should use once your project is at a large enough scale that you need it. You can go a long way in vanilla React before you feel the pains that Redux (or Relay) solves. The React part of my current codebase is over 25k LoC and I still don't feel the need to throw Redux into the mix.
Take a peep at http://djcordhose.github.io/hh-react-conf-2016/redux-vs-rela...
If you're just starting out then first spend several weeks/months in vanilla React. Unless you need to learn Redux to work on a bigger codebase at a new job or something...
Qualification: I used to work on React Native at Facebook.