Featured Image on Front pae

Hi everyone,

Im new to this so bear with me please. I just got the Shell theme to set up a small business website to attract new people. Now, im having a issue changing the “dear” image on the front page, which im certain would be named the featured image.

Can someone help me as to what is needed for me to change this? Or is this a permanent image that comes along with the theme? Your help would be greatly appreciated.