Aljaxus

Firefox, love every part of it.

FFmpeg works great, like e.g. ffmpeg -i video.mp4 out%d.png

I am no "professional" by any means - I am not even fully employed - so take this with a grain of salt...
And keep in mind - everything is just my opinion
 
I will not tell anyone what to do, because I don't have enough experience in working field at all. All I can tell you is the following;
 
I am just 18 years old, though with decent experience in full-stack development, and I am "partly" employed in a semi-large company as a programmer - I can't be full-time because I'm still a student (and laws here, etc..). I develop internal applications with "progressive" technologies such as NodeJS for backend, VueJS, Webpack, Service workers for frontend, etc...
 
The company is selling machines for casinos, machines themself (hardware) and software. Their software is written in C, C++ and maybe they'll switch to Java if they'll start a rework at some point.
 
C++ and Java are quite popular in the fields of gaming industry (gaming as "casino gaming").
There are also loads of applications for internal company organisation which are all written in Java and C++
 
If you're looking to get in some more "current-gen" work you should look into mostly web-related technologies.
Get familiar with Javascript, NodeJS to be more specific, and at least ES6 if possible with latest standards. If you will follow the NodeJS path, you should also look into GraphQL - a very good standard for HTTP API development. Look at it like an improved version of RESTful API standards (you should also learn at least the basics of RESTful APIs).
Don't forget about MongoDB - it's a bit weird if you're already familiar with MySql, but if you're starting a new project and you can pick between those two, I'd go with Mongo. It needs a bit more setup, but it gives you much more freedom and flexibility.
 
Speaking of Docker - learn it. It's very easy, it will help you A LOT. Especially when you're working on some backend stuff. In most cases servers run on linux-based environments. Docker helps you run your backend app in linux environment, while you're using Windows - without any virtualization. It's great - lean it.
 
Long story short... In my opinion you can't go straight to some language / technology and be like "I will learn this because this is what it is used at the moment" because at the time you'll get good enough, it might not be an industry standard any more. Well this probably doesn't hold true for C++ or Java, but it might for some other technologies.
If you have enough time - find some interesting, yet easy, project and try to complete it in a few different technologies.
You should learn how to use Docker in any case.
 
This post might be a bit messy, if anyone thinks I should correct something or needs some explanation, please `@` me.