If you are new to git and github, to make your first contributions, visit this: Hello World.

If you prefer reading, then these are some of the curated resources you can refer:

• Geeks for Geeks: C++ Programming Language
• CodesDope: Passion Matters, Not Age
• TutorialsPoint: Learn C++, Simply Easy Learning
• learncpp: Tutorials to help you master C++
• cplusplus.com: C++ Tutorials

If you prefer youtube videos, then these are the best ones out there:

• Programming in C++ Playlist

If you prefer MOOCs, then refer the following:

• edX: Intro to C++
• NPTEL: Programming in C++
• Udemy: C++ Tutorial for Complete Beginners

For any reference on C++ libraries, refer to cppreference.

You can go through the Getting Started folder to read and practice some of the basic programs of C++ and also contribute your own programs (if similar program not already added by someone else).