Google AdWords Fundamentals exam covers basic and intermediate concepts, including the benefits of online advertising and AdWords, and best practices for managing and optimizing AdWords campaigns.
Google Search Advertising exam covers basic and advanced concepts, including best practices for creating, managing, measuring, and optimizing search ad campaigns across the Search Network.
I tried twice but failed. Can you suggest me any reading materials?
Did you go through the study materials on https://academy.exceedlms.com? Follow then carefully and that should be good enough to pass. Good luck!