How to Organize the classes of a low level design in code blocks IDE

I am having an interview where I have to do low level design coding in an IDE which I have choosed to do in code blocks IDE . So I have question of how to organize different classes of that design. My point of asking is if I have 10 classes should I create all 10 different classes in a project by adding every time a new class. I think it would be bad approach. So Is there any other approach to do so.