I've had an ecommerce website created by a web design company before, but I want to do a new one on my own.

I have a domain, I have a host, I have a logo, I have a supplier, I know how to list an edit products, I know how to market, I JUST DON'T KNOW HOW TO DESIGN A WEBSITE.

I know that's the biggest part, so I'm just wondering what is the best way to design an ecommerce website for a beginner.