Gimp Illustration

I was wondering if you could help me make a Gimp design. I want something similar to the photo attached below, except the setting should be a library and there should be an umbrella hidden in the photo. There is a contest to find the umbrella so it should be placed discreetly but not too hard to find. I would need it to be finished maximum September 1 and am wondering what the quote would be for this project!