https://isocpp.org/get-started
https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines
https://en.cppreference.com/w/
If you are looking for books then start with (in the given order)
- A Tour of C++
- C++ Primer
- Programming: Principles and Practice Using C++
- The C++ Programming Language
- The C++ Standard Library: A Tutorial and Reference
Why not Go, D, or Rust?