Firstly, I'm not formally educated in programming or anything similar.
I would really recommend C++ above the rest, I found parts of it ridiculous while I was learning the basics but now I am glad C++ is what I focused on.
I'm not a real fan of programming in Python, it can be a useful tool for scripting and automation, but I do view it as a tool rather than a "proper" programming language, I've never looked into the Python SFML binding.
I'm pretty sure the .NET binding is very close if not the same as the C++ one, if you are interested in a .NET language.
If you already are learning C++, I say stick with it.
Hopefully this is of some help and not just confusing
Converting numbers to strings pisses me off too lol