Can't find file to modify template

I’m working with a template that a customer of mine got off template monster. I don’t have the name of the theme. I need to modify the text on the “Portfolio” page but I can’t find where the text is written. I opened the “Portfolio” page under “pages” but the actual body is empty. I then checked the widgets and that was empty as well.

I also need to add photos to each of the pages under the portfolio menu. Only the Portfolio page itself list the images (and it list all of them, no matter the category}. I created a category for each page under the Portfolio menu, but the images don’t link to the assigned page. View images here:

https://i295.photobucket.com/albums/mm145/cptrainer01/help.jpg

https://i295.photobucket.com/albums/mm145/cptrainer01/helpinspect.jpg