if the shell your using dosnt recognize a command, this is due to one of two reasons.
a. the command dosnt exist on your system. it is not installed.
solution: find the program online, download it and install it!

b. the location of the program is not in your $PATH.
solution: find where the path to the executable is located, and try running the program with the full path.

the best place to get started with c++, www.google.com