Hello Rams,
there is extensive library of examples already written, all you need is to try it:
for data driven testing and how to get data from DB/excel, check this tutorial:
for API specific topics this tutorial is what you are searching for: https://docs.katalon.com/katalon-studio/tutorials/api-testing/index.html
spacially last part, manual creation of API request
if you run into any problem, just ask with specific informations an detailed description of your problem.