How to learn DICOM

Hi Geanters:
I’ve recently been learning DICOM examples to implement modeling through CT images. But this example is too complicated for a newcomer like me. In this I am looking for some information or advice on how to learn this example. If I simply want to build a model from CT images I need to copy those files from this example.
Thank you all for your answers, your advice and guidance is really important to me as a newcomer!