Coaching or standard books?

I'm currently a first year student at one of the top nlus and I plan to clear upsc after graduating.i have about 4 years for my prep. How should I plan my prep?( I have a humanities background)

  1. Should first complete all the standard books and make notes after proper readings(till third year) Then supplement them with coaching classes

  2. Or should I first go with coaching classes and make notes Then supplement the notes with standard books?

Pls give suggestions 🙏🏻( can dm also for better communication)