Elements 2021 Layers versus filters for image editing

[dianef31111009]

having recently finished digitizing more than 1000family photos from 1880s on, I Purchased photoshop elements 2021 with the hope of enhancing and restoring  images during  What I predict to be a long, cold Covid winter 2020- 2021. I've read as much information as I could, watched older versions of Photoshop elements in Linked-In classes. I understand there are three modes, quick, guided, and expert.

I want to tackle expert for this project. my first question is regarding the tab "enhance".

1. I've read that I do not want destructive editing, but how is this a problem if I enhance on a copy of the image?

2.  I'm also confused regarding whether I would use filters or layers to edit an image?

Without anyone to help me face-to-face, this has been a frustrating albeit excellent challenge for me.

[dianef31111009]

This photo is not 1910 (I do not know how to delete a post in error), but rather one of a series of photographs that I scanned. It dates back to the 1860s, the 13th cavalry in Texas during the Civil War. 

I scanned photographs of long lines of cavalry marching in a city, of skirmishes, and the like.  I will tackle those after I have gained facility with editing.

I am very impressed with the initial editing you applied to the photograph. Thank you.