Over holiday break I was reading Shankar's QM book. I got through and really enjoyed the first chapter, which goes over required mathematical tools.
The second chapter goes over Lagrangian and Hamiltonian mechanics, which was much harder to grasp. I find #physics almost requires some sort of lectures, whereas math can be learned from a book.
Luckily I found a lecture on YT by Prof.V.Balakrishnan on the topic of Lagrangian mech: https://www.youtube.com/watch?v=sCZ80l6UarM . Very clear, wholesome and insightful!