Excellent start to a professional career by already researching requirements and necessary steps to be taking in pursuit of your dream! It certainly helps to be informed and proactive.
Yes, that is one of the challenging and unique aspects of applying to PA schools - the variety of pre-requisities and even the language that is used when stating those courses and clinical/patient care hours - "strongly encouraged," "additional courses" - it makes you wonder which courses are essential to have taken to be considered as a competitive applicant. Personally, I started researching earlier because I wanted to prepare my undergraduate course load so that I could increase my chances of being considered at more schools. And if you decide to wait until later to prepare your course load, that is totally fine - you just may need to take summer courses to be able to apply - so that depends on your finances and personal timeline/plan. All this being said, I still would say enroll in courses that captivate you as your grades and life will be affected...in essence, still be you! Enroll in courses that are of interest to you as well. You will still likely have to take the daunting biology and chemistry classes - but with a balance of these classes, you will then enjoy your college experience as well. Hope this response helps! Best of luck in your future endeavors!