I would not get bogged down by webpack/es6/babel/redux/immutable. I would only focus on learning about React and React only the way they have shown in official docs.
I would not go through so many 'starter kits'.
Dos
I would begin by learning through Stephen Grider's React course on Udemy.com
I would build my own simple app only using React. And at a later stage I will port it to use Redux.
At this stage I will learn about immutability and its importance in Redux apps.
Study through other people's code on github - Sound-redux and itsquizwall repos. These live apps that are actively being developed on Github.