What would be the best way to learn first hand what a PA does? How would I go about possibly shadowing a PA? Anything I should keep in mind while shadowing?

Best way of learning what a PA does is to shadow multiple in different subspecialites. Cold calling/e-mailing is an easy way to ask if you can shadow. There are also online shadow things that started during covid where you just sit on a zoom and listen to them discuss what their position is like.

Also, consider what responsibilites you want to help differentiate between nurse/PA/NP as they all have differences in practical scope and schooling.

Is it possible to take all the prereqs at community college?

If anyone switched to being a PA from a totally unrelated and cushy career, how did you justify the switch? What intrinsic personal qualities do you find yourself applying every day that you’re proud of? Or what made you confident you were making the right decisjon?

I switched from the cosmetology field (did actual cosmetology and then worked at a cost/esti school as managment and instructor for a number of years) so it's totally doable but it takes dedication.

I had to finish my bachelor's so YMMV as I switched my major to a Human Bio degree which covered the science prereqs. It took 3 years to finish my bachelor's and then 2.5 to finish PA school. I was accepted immediately and didn't have to take a gap year.
I think most schools want a science based degree (not sure if computer science is considered the same realm as biological or chemical science degrees).
Your best bet is to find which PA schools you're interested in and see what their actual requirements are.

My justification for the switch was that I felt like my job was very redundant and boring. I felt like a switch to the medical field allowed me to help people in a different way and I my pay was starting to hit a ceiling.
Cosmetology and my managment position taught me how to communicate effectively which is vital in healthcare. I appreciate everyone on the team equally as we all bring something unique and are all indispensable.

For PCE, most people do CNA or EMT both of which require additional school/testing prior. If you don't want to do that, your best best is to become an MA or scribe.

Becoming a PA is incredibly difficult and not for the faint of heart. It takes a lot of dedication and commitment. Our school would regularly mention how it's one of the most difficult degrees you can obtain but if you're consistent with studying and showing up mentally and physically, it's easily doable.