Change about section and bottom field.

Hey I am noob at this. I just downloaded the free fotografie theme (I want to buy it, cant find it anywhere though), and I want to change the text in the "about" but cannot find any menu for it. It looks like this: https://imgur.com/a/AfO6b. I would also like to change the size of the block, hope it makes sense and someone can help me out! :D