Hi, on the main toolbar, at the left end of the "address bar" where you see the URL of the current page, there should be a lock icon. Does your Firefox show that? If you have some desktop showing, you can drag that lock icon to the desktop and release the mouse button there to create a shortcut back to the page.

If you need a local copy of the web page, what do you think about saving a PDF copy? When you call up Print, one of the "printers" on the Destination list is "Save to PDF".