You've got 3 options

1. If you want to do FP (you might want to also look at Learning FP):

Functional Programming in Scala

but if you already know some FP, or just need to dive into an FP codebase, you might need

MaxwellBo/A-tour-of-Scala

2. If you want to do Big Data:

Big Data Analysis with Scala and Spark

3. If you want to do Actor Model model stuff:

Introduction to Akka

If you're wondering where to start, it might be worth checking out how the industry actually uses Scala:

Scala 2019 - The state of Developer Ecosystem in 2019 Infographic