Breaking into quant roles

Hello,

I am a rising freshmen going to Williams. I have my eyes set on entering quant trading at prop trading firms such as HRT, SIG, DRW, Citadel and the likes. My goal is set and I am determined on landing one of these jobs. I want to prepare as soon as possible so I can secure an entry level job at one of these places. What steps should I be taking/how should I be preparing? Are there any books/topics I should be learning and mastering in my free time? I am planning on double majoring in applied math and economics. What should my timeline be from freshmen year to senior year? Should I get an internship every summer? And what kinds of internship do I get? I want to come into those quant interviews and absolutely ace it. I know it is much easier said than done, but I am willing to work, work, work. Any advice and guidance would be greatly appreciated.