Modify WP Theme to add text to images in Media to display

Hello, I have a WP site [login to view URL] (artemis) and I want some code written to add two lines of text to each image that is clicked under the Profile/Lifestyle for example page. Text needs to be added to each image in the Media section in WP i.e. Photographer is Easton Lee, Makeup is Peter Jones, Copyright etc.. These do not have to appear anywhere except on each picture as each picture is different. I do not need for SEO purposes. So not sure if you need Alt Text or Caption here etc..? This site is a Photographer/Model site and of course each picture needs to have text added to it. Please quote me.