There's no copyright symbol on any common keyboard, but it's easy to insert the symbol whether you're using Windows or a Mac.

Windows includes a variety of special symbols that you can enter as text, even if they don't appear on keyboards. You can get a copyright and registered trademark symbols, which appear as a "C" or "R" ...

You can add a superscript or subscript in Google Docs by selecting text and using the Format menu or through keyboard ...