Quant developer Roadmap (4.25 years)

Hi, I am a high school graduate and figured I want to become a quant developer cause I like maths don't know about coding (haven't started it yet). I am going to study in a tier 1 clg bits pilani in India computer science course. I have about 4.25 years till I graduate I am earlier than most people atleast in my country and i actually like to study not more than 12 hrs per day though 12 hours per day is the sweet spot for me. I need your help in guiding me how I can start i have like 3 months before my classes at the college start so if you could guide me what I should do in this time it would be really helpful. Thanks!