Does it specifically have to be a business site? My advice would be to choose a topic that interests you, because that way you'll have more fun doing it. Do you belong to any kind of church, club or community group that might appreciate having a site built for them? Do you have any hobbies or interests you could use as a basis? One of the sites I've most enjoyed working on is for a local quilters group, a not-for-profit group who do a lot of charity fundraising. It's an informal site and I just had fun with it. (I'm not a quilter but I enjoy other crafts, so the subject appealled to me.)
If it has to be a business, then small businesses such as cafes, guesthouses, riding schools or cycle hire might be suitable. You should be able to write your own text, and if you do a Google search for images available for use, I'm sure you'd find some you could use.