I was in the same boat a few years back. It's great that you are thinking about your personal statement already, but it's kinda unnecessary. What you need to do is focus now on interesting ECs that you can add to your application. For example, study abroad, working more closely with some physicians for possible LORs, or even trying to shadow physicians in a variety of specialties. Pretty much, you have a lot you can be doing other than your PS. Your PS should really be a statement of what has brought you to choose medicine over your entire life, especially over the course of all of your college years up to that point. Thus, if you begin working on it now, it might be somewhat of a waste of time because you don't know the impact different experiences will have on you over this next year. Good luck with everything!!!