Hi Mahir,
Here's what I recommend:
1) An initial planning session with a coach: 1 hour with a coach now will have a productivity multiplier effect on all your efforts moving forward. They will figure out what materials are best for you, guide you towards the best ways to learn, and come up with a preparation plan with you.
2) Leverage free resources first: PrepLounge Q&A and case library, Poets and Quants, SpencerTom, Google, etc.). Leverage these options, read-up, and build that casingknowledge
Importantly, read The Economist, the Financial Times, McKinsey Insights, and BCG Insights daily to build up your business knowledge.
3) Case with other PrepLoungers: Casing with other PrepLoungers is free. Not only do you get to practice casing, but you get direct feedback. Additionally, you learn a lot just from casing others. Finally, from other PrepLoungers you'll learn which materials/coaches are helpful.
Read this for Case Prep: https://www.preplounge.com/en/articles/how-to-shift-your-mindset-to-ace-the-case
Read this for Fit/Behavioral Prep: https://www.preplounge.com/en/articles/tell-me-about-yourself-interview-question
Another Q&A: https://www.preplounge.com/en/consulting-forum/what-are-the-best-preparation-materials-and-how-to-prepare-the-whole-journey-in-the-most-efficient-way-6142