If this helps, it's designed for unstructured information storage, so fundamentally you use it as you'd use a notebook with the exception that organisation is something you can do ad-hoc. For example ...

For years, OneNote has been my trusted companion for capturing thoughts and organizing information. While it comes with a robust search function, I wanted a system that actively engages with this ...

As part of its massive November update cycle, Microsoft on Thursday pushed a smorgasbord of new features to its OneNote notetaking software across a wide variety of platforms. Users of OneNote Online ...