Thank you for your question.
The “doc” file that came with your theme download is the documentation file, which contains instructions on how to set up and use the theme. It’s a read-only file that you can open on your computer to learn more about the features and options of the theme. However, the actual theme files are contained in the “theme.zip” file that you downloaded. You only need to use the “theme.zip” file to install the theme onto your WordPress website.
So, in summary, the “doc” file is a helpful resource for understanding your theme, but you only need to use the “theme.zip” file to install the theme onto your website.