Agree that reading RP doesn't hurt but not reading it won't hurt either.
However, if you have extra time on your hands between now and I-Day, it's BEST SPENT GETTING IN GREAT PHYSICAL SHAPE. If you don't have to struggle mightily through PEP, the O-Course and the other physical stuff they throw at you during PS, you will be much happier, much better off, etc. And, in that regard, the best use of your time is spent running.
If you're a great runner, stick with it until I-Day -- don't slack off once organized school sports end in April/May. If you're an average to lousy runner, find a track coach, a personal trainer or someone else who is knowledgable and develop a program NOW. (Yeah, USNA sends you a workout plan which is fine but, which in my opinion is too little too late for people who aren't in pretty good shape when they get it.) The worst runner can make HUGE strides in the next 6 months, which is what you have if you start today. Don't wait for the good weather to come, start now.
And, if you're a terrific runner who can do pushups and crunches for hours on end, then go ahead and start memorizing Reef Points if you really want to but . . . as the above posters said, don't show up your classmates if you do.