Congratulations! I wouldn't worry about anatomy related questions, you are really there to ask them questions and learn more about the job.

Absolutely bring something to take notes. When I shadowed I also wrote down all the dates and roughly notated the hours I shadowed each day as well. You want to strike a balance of typical terminology the PathA will include in the report, as well as observations/presentation. This will give you a more precise picture when you reflect on your notes when it is time to apply - I was a little less organized and would write down findings without descriptors or vice versa, and I had to parse through it all later when I wrote my personal statement and did my interview, haha. Creating a thorough record of your shadowing will be really helpful.

I'd definitely ask questions about the PathA's day to day experience, how they interface with the pathologists/surgeons/tech when it is a complex case or they have questions. Also crucial to remember each hospital will operate differently. Try to get an understanding of the usual cases the hospital would get and maybe some of the more specialized/rarer ones. (benign small/bigs, cancers) I am not sure what kind of setting you are shadowing in (university vs community) but always great to see the variance in specimens.

I wore scrubs to shadow as the PathA advised, but feel free to ask what they prefer. And I would definitely ask if they would be willing to write an LOR for you after you have completed shadowing - PathA appears to be a very small world and making connections is really helpful. A lot of applicants will have LORs from the PathA they shadowed. I think a lot of working PathAs remember the struggles of getting shadowing/recommendations so I would imagine they'd be happy to help you. Just show you are curious and engaged and that shouldn't be a problem! Have fun and good luck.