Need help with API testing

Hi there…
I am new to Katalon studio. My aim is to perform the API testing which includes much complex scenarios than just comparing the status codes.
Here’s the scenario…
I have different lists maintained in excel sheets.

  1. I want to get the values from the dropdown list via the rest API and store it in another excel sheet and compare the two sheets if anything is missed out.
  2. I need to create a json file to be posted through API
    However, I don’t find any related documentation or videos to perform such kind of operations which involves getting data, storing it and performing logical operations on it.

Can anyone give me an idea on how this can be achieved in Katalon studio?

@sejal.supariwale There is an excel plugin that can help you in reading and writing to excel.

For the 2nd point, I think you can use variables.