I was looking around and found these two that I think look good.

https://www.freepik.com/icon/open-book_3441370#fromView=resource_detail&position=23

I like the icon and the color because it stands out.

https://www.freepik.com/icon/book_5119230#fromView=resource_detail&position=6

I also like this icon and the depth with the “shadow”.

Does anyone else have any recommendations?