Have you learned the basics of C++? Like the basic structure of a program, variables, functions, etc? If you have that stuff down there is little else I can do. Classes are the very basis of OOP, like variables & functions are in procedural programming.
Study it online or out of a book somewhere, look at examples of classes. It's basically calling functions from a separate file, not much different that calling a normal function in a main.cpp
trouble with classes