How do I create a custom parameter set to add to Chat Gpt 4o

How do I create a custom parameter set to add to Chat Gpt 4o so that it does a very speficic set of actions on a document. I am trying to create a standard prompt or layer that can read through a document and take line by line and categorise it so that I can change the categories for each docuemtn and it will follow the same format and process consistently, just sort information into a table under these categories which are a movable input. I am new to working with this kind of stuff but would really aprpreciate some help

Take a basic python course. 2-3 days and you can do it.