Documentation for programming languages

All kinds of textbooks and books are good, but they are usually offered for purchase and often not exactly cheap, even if they describe the basic level. The free solution is obviously the official documentation. When I opened the python documentation, I was pleasantly surprised that it was written almost like a textbook. For Java, everything seems to be relatively good in this regard, although I would like a separate offline pdf.

I wanted to download documentation in a similar form for C and C ++. I went to their official websites, where they offer to get a description of the standard on the ISO website for a considerable amount of money. And the very description of the standard is far from being for learning. Well, I thought, then I’ll try to look at the documentation for one of the language implementations - GCC-CPP, and I see that what is described there is also not at all suitable for learning. There is not even a description of the types and examples of the declaration (maybe I was looking badly, but I didn’t notice it in the headers).

The question is the following: is there a normal available free documentation on which you can learn C, C ++? Official documentation for other languages ​​would also be interesting.

This may help for C++:

There are also tutorials there for C and C#.

Thanks a lot!