They're both used heavily in industry, learn both. Python is probably the easier of the two to learn unless you've already got some C background in which case Java will seem more familiar.

I love the Bjarne book. Excellent for learning as well as reference. My copy is dog eared from use.

Check out MariaDB instead MySQL. They are both very powerful dbs now and the choice is really what you are most familiar with.

The Linux kernel is a great project in C.

There's a whole lot of Scala there, so unless you plan on learning that too you can easily skip that content. Their major technologies are Akka (an Actor framework), Play (netty based, async, non-blocking http framework), and Sbt (Scala based build tool - juiced up Maven). Obviously their channel will focus on this stuff. It can get a little heady, but I love being able to solve problems in new ways!

I don't know how well they present for beginners, but the Typesafe channel is full of great videos. They're always presenting some of their new technologies complete with examples.

Competent business leadership that empowers rather than hinders innovation.

If you read man grep(1) you'll see that your -q option suppresses output. I don't think you want to do that since you're using the output to build an array of values.