Programming languages exist so you can do something useful with the computer.
C is awesome and is probably as fast as you're gonna be without something like Assembly or machine code in hex.
You can view documentation for many programming languages, as well as other tools, on https://devdocs.io
https://www.programmingsimplified.com/ → great resource for C and C++
https://choosealicense.com → help on choosing a license for a project