How to author name for theme – Wu Wei

I just setup a new blog on WordPress.com, and have chosen the theme Wu Wei by Jeff Ngan. The problem I’m facing is that the theme doesn’t show the author’s name on the posts by default.

From what I could gather online, I need to add a Template Tag (which I don’t know how), or edit the theme (but the option Appearance -> Editor seems to be missing!).

I’m new to this system, so will appreciate if someone could help guide me to how I can add the author’s name to the posts please..

Thanks!!