Seriously, how should a community based on short two- to three-paragraph answers react to question after question like this:

I am new to python. I would like to write a program which can collect information from multiple excel and pdf documents to output that in one single excel document to show similarities and differences between the documents . Is this possible ? If so, how and where would I start writing such a programme in python? Thanks

I haven’t tried anything yet

I mean, I'm glad that someone looks at that problem and thinks "programming could do this", because it could, but it's kind of a big task and getting someone from "I haven't tried anything and am brand new to python" to that is beyond any question-and-answer forum. Welcome to programming, you may be able to get there, but it's going to be a bit of a hike.