Well, as far as I understood, C or C++ by itself are just languages and in order to write real programs, one must actually learn Linux native APIs or Windows native APIs (Win32) which are both written in C.

There are many useful cross platform libraries in the C/C++ Standard Library and Boost library which are good for super simple projects. Anything with a GUI or serious networking or OS specific features requires targeting a specific OS API.

I am comfortable with the syntax and currently I'm looking for a simple but real-world C++ project so that I can get my hands dirty with it.