I think it was Dan Abramov (the creator of Redux and quite a few other things in the React ecosystem) said to start with React only; then, when your application gets complex enough to need other things (Router, Redux, etc.), you'll know it.

And you'll know it because by starting simple, you won't get overwhelmed - and you'll build up the knowledge you need to move to the next level.

As for where to start, either here for "text" only: https://facebook.github.io/react/docs/tutorial.html

OR

here for video: https://egghead.io/series/react-fundamentals (although I think it may require a subscription).