Why are you advising him to run before he can crawl? All of those paradigms are built on top of the 70's era threading-model as used by the JVM (as well as every other language, behind the scenes).
How can you understand these tools thoroughly if you don't understand the foundation that they're built on?
Yes, they probably have been used in services with billions of users, but I guarantee those engineers understood the basics of threading just as well, if not better, than the tools built on top of them.
OP: This video is pretty good at explaining some core concepts:
https://www.youtube.com/watch?v=MCs5OvhV9S4
