Here's a You Tube clip about the process most people go through when setting up a website:
In summary, it's about moving from building a website for yourself (putting stuff on there that pleases you) through to building for the user. This means understanding what your customers want, need and are willing to buy, and reflecting that on your website. This requires conversations with your customers, so that you understand how they think.
The good thing about websites is that you can change them whenever you want. So it's perfectly okay to take that first imperfect stab!