I would set up the schedule from now to the date to the PCAT. That way, you can see how many prereqs you need to take in combination with your other requirements and schedule accordingly. Spreading them out optimizes your chances for doing well in those courses unless you have a desire to take upper-level science courses to get the theory behind the basic sciences. If you are considering a degree, do remember that you have to account for that as well.
If your goal is to go to pharmacy school that makes the junior and senior years as fall back options, then I would worry just about fulfilling all of the prereqs tested on the PCAT first, then the other prereqs, and then worry about the possibilities about other courses then. This strategy is called prioritization.😉