Choosing a theme

Hi all, hopefully this is the right place to ask this question. I’m new to WordPress and am trying to pick a theme, but there are so many to choose from! We are starting a website that will provide detailed solutions to submitted problems, not an actual product that would be ordered and shipped. I need e-commerce capabilities, account login, and a shopping cart, but most of the themes I’m seeing are product driven. Can you point me in the right direction?