It really doesn't help when we don't know what the error is.
I get 2 undefined references:to "Website" constructor and to "User" constructor.
I have a muti-source program:classes.h, implementation.cpp, and main.cpp.I defined all my classes in classes.h and #included classes.h
and implemented my classes in implementation.cpp .main.cpp contains my driver program
it would also help if you rewrote the program using std::array/std::vector and std::string.
The error basically means you are trying to call the constructor of the Website class and the User class and they have no implementation that is linked.