If you want to learn Scala, I’d suggest:

Install IntelliJ + Scala Plugin
Don’t do the Coursera courses yet.
Don’t do the “red book” Functional Programming in Scala yet.
Do: http://underscore.io/books/
- Essential Scala
- Essential Play
- Essential Slick
Do Scala for the Impatient: https://www.amazon.com/Scala-Impatient-Cay-S-Horstmann/dp/0321774094
The Neophyte’s Guide to Scala http://danielwestheide.com/scala/neophytes.html
Write Scala code for a few weeks/months.
Do pair programming with experienced Scala devs.
Install and configure scalafmt http://scalameta.org/scalafmt/
- Just focus on the code, not the style.
Go to gitter channels, people are really nice there.
- https://gitter.im/scala/scala

Improving Scala/FP/Reactive Programming

Akka
- Akka in Action https://www.manning.com/books/akka-in-action
- Effective Akka http://shop.oreilly.com/product/0636920028789.do
- More: http://doc.akka.io/docs/akka/current/scala/additional/books.html
Read about SBT (but not too much)
- Keep your build.sbt simple, the less, the better.
Install ammonite
Stop using IntelliJ compiler, it’ll eventually lie to you. Always compile on SBT.
Start reading the “red book” https://www.manning.com/books/functional-programming-in-scala
Don’t throw Exceptions, use ADTs, Either
Do Advanced Scala with Cats (underscore)
Keep reading the “red book”
Keep and eye on: Functional Programming in Scala for Mortals
- https://leanpub.com/fp-scala-mortals
Functional and Reactive Domain Modeling
- https://www.manning.com/books/functional-and-reactive-domain-modeling
Keep reading the “red book”
Read more blogs, twitter about Scala.
- From time to time, they will fight, just ignore them.
read.andThen(practice).recoverWith(read)
If you have plenty of time do the Coursera Courses (not sure if it’d worth it)