To be honest you are supposed to be a designer. You have taken on this job for the client on the understanding you can offer them a professional looking design. If even a simple good design is beyond your skill set then perhaps you should think of a change of career?
Just coming on here expecting other people do to do your job for them with no coherent feedback isn't going to get you very far.
If you have already done one site, then use the same design for this one. Go to any Walmart store, what do you notice about their branding on all of them? The idea of branding is so you can go to a store anywhere in the world and instantly know it is a Walmart