When to start? How to start?

So, forgive me if this isn't the right place, but I'm preundergrad and really stumped by the magnitude of knowledge I have to acquire for the MCAT. I'm a paramedic so I thought I had a fair grasp of some of the basics but there's so much extra knowledge I have to learn and I don't even know where to start.

I was planning on going to university for public health, and then getting the med school prereqs done as well, and then going to med school, but the wealth of knowledge needed for the MCAT doesn't seem to be adequately covered in university unless I do premed.

Am I missing something? I love science and I love medicine but I feel like I'm staring at a hill that leads to the moon, and being expected to climb it. Where do I even start?

As an aside, ex Ukrainian SOF medic. 2 years civilian EMS. Hoping to specialize in EM, subspecialty in disaster medicine. If that changes anything.