Can't find active theme data

There are a few ways I can think of to find out what your active theme is. The first is on your Dashboard. It tells you in the At a Glance Dashboard widget. It says something a long the lines of

running [theme-name] theme.

The second is by going to your Appearance page. That will show you not only all your installed themes but the active theme as well.

Let us know if you have any further questions!