C is the way to go my friend. The popular languages such as Python which you mentioned, are just C in a trench coat. It's all abstraction. If you understand C, you will be able to understand any language.

I'd go with php, it can be strictly or loosely typed, has C-like syntax (same as C#, Java, C, C++, Javascript and others) and has a huge standard library built-in, so for a lot of tasks you don't even need an external dependency.

This won't be very popular, but something with manual memory management. You probably won't use it a whole tonne, but that's not the important thing. The important thing is the understanding of memory concepts such as addressing and pointers.

Personally I learned C++ first, haven't used it a whole lot, but it absolutely helped me understand other languages much much much better.

For mechanical engineering, any thing computer or programming related will be

Python and C/C++

knowing your way around MATLAB.

and maybe possibly Ladder-Logic or Function Block. (PLC's and the like)

All depends on what engineering you end up doing. But Python is a good place to start.

Python or Go.

I recommend people try learning Python through Jupyter Notebooks as a first attempt. It’s nice being able to run individual blocks of code and auto printing of output is great for learning more quickly.

Go is just a generally straightforward language and is known for being productive after a short time of learning. Plus generating binaries that can run anywhere can be a motivator if you’re planning on sharing the output of your programming.

Another vote for Python. It's quick to learn the basics, and there are libraries available to let you achieve most anything. You can program it in a procedural, functional or object-oriented way, and if you understand those, you'll be well set-up to learn any other language. You may not need to learn any other languages - Python is both comprehensive and available in most places, and you can make a career out of it.

My primary problem with Python is that its unstructured nature causes bigger projects to collapse into a big ball of mud after a while - any function being able to accept any argument is more of a curse than a blessing. And I wouldn't want to code collaboratively in it - Java, for all it gets shit, is blessfully limited in what nonsense my coworkers can get up to.

It's also not 'fast', although it's made great strides. I did Advent Of Code in Python this year; a simple rewrite in C++ only acheived about a 4× speed-up, when it used to be 10× a few years ago, and that's for some very algorithm-heavy code. Python multithreading is still pretty terrible, though, so if you're really wanting to get the best out of your computer you'll want to use a native-code library like NumPy, or use some other language.

I think JavaScript is a great first language. Easy to pick up, but lots of potential (frontend/backend/native). A lot of people dislike JavaScript (some valid reasons, some not) but it's undeniably a great first language.

To flip this around, think of some projects you want to do. The languages are just tools and will be determined by what you want to do, and then each type of project has it's best tool chain. Think of the problem(s) you want to solve first and the rest will follow.

Wanna learn something completely different yet useful? Check out OpenSCAD - it's a very simple programming language which lets you generate 3D models that you can then export and 3D print (you can also export 2D models in vectorized 2D formats like DXF and SVG)

Really simple software to learn, but extremely empowering when paired with a 3D printer

Python is good but the syntax is quite different from what you get in most other languages, so if you then want to learn another language you might find it a higher learning curve than if you learnt something like Java or Javascript