Hi Dimi,
Rob Percival has amazing videos on Udemy, I highly recommend them.
What are you thinking goals wise?
If it's just for intellectual curiosity then maybe C is a place to start. However as a beginner I don't expect you to understand the build system "make" early on or even use it to good effect. But you can write some trivial and non trivial programs in C and learn a lot. If you are interested in Computer Science and are bored of C tutorials, try writing an autocomplete program. Load it up with a dictionary and use console input to give suggestions when ever you type a character onto the screen. My company once used this as part of the coding part of the interview process.
If you want to be able to write an application (think a webservice or maybe even your own start up idea), That is when you want to try out a language like Python, which is great and lets you achieve a hell of a lot in a small amount of time. I personally love Python and I have mainly worked in the start up space on ML and NLP using Python to first understand the problem space and a possible solution. Ruby is also an equally good language that helps you to get **** done.
You can even try Java, I write code used in serving ads based on ML/NLP and for something that gets a huge volume of requests an hour, I prefer statically typed languages like Java. Also Java's concurrency primitives and libraries are very well documented and easy to use, you also get the JIT optimisation which can seriously reduce latency once you have warmed up the JVM.
Most important thing tbh is just get started, what ever language you decide. Most of what you learn is transferable.
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