Much to learn and much to do
But, you still have much to learn and much to do before you will need to define new types.
There are a lot of fundamental programming concepts that you will need to learn before you seriously embark on a study involving the definition of new types.
For the present then, simply remember that such a capability exists, and if you work to expand your knowledge of modern object-oriented programming one small step at a time, you will be ready and eager to define new types when you reach that point in your education.