My undergraduate program had a similar P/NR system for our first semester of freshman year as a way of helping students adjust to the college environment. I ended up taking my introductory biology, general chemistry and physics I courses and got a P for all of them. P/F thus doesn’t look too bad given the context of your undergraduate
That being said, you should try to take as many of your courses on a graded scale, particularly major medical prerequisites. Your GPA, after all, is a component that medical school admissions looks at since it is a rough indicator of your ability to perform academically (which is fairly important when it comes to studying in medical school).
Tabrez Alam, M.D. from SUNY Downstate Medical School (2023)
Source: Quora Digest