I am new to LibreOffice Writer, having used Microsoft Office Word for many years.
In Word, when I insert a copied image into a document, I can go in and re-format the image, sharpen blurry, indistinct images, etc.
How do I do this in Writer?
Select the picture (one click) and look at both, the toolbars and the sidebar. There is a toolbar called “picture” and a section of the same name in the “Properties” tab on the sidebar that offer a lot of tools to apply filters on top of your image (blur, sharpen, black&white, etc.)
Note that you’re not changing the picture, but applying filters on top of it, and AFAIK Word does the same. The best way to really edit a picture is to use a dedicated tool like Krita or gimp before inserting it in your document.