Just figuring out the optometry school requirements is a difficult process in itself! Rather than going to each school’s website, you can view an aggregated list of optometry school requirements for every school here.
If you want to get a sense of what GPA you’ll need to meet the optometry school requirements, you can view the statistics on the most recent entering class here.
In terms of pre-reqs, Anatomy, Physiology, and Biology 1 are the classes that have helped me most in my first year of optometry school. Optometry school is pretty Biology heavy (so far at least).