Themes that are VERY Beginner Friendly

I have been poking around trying to find a theme I like that I can customize for a new single product small business site. I have NO experience in website design. So far everything I’ve activated has an interface for customization that might as well be in a foreign language for me. Any suggestions the most user-friendly themes for customization? I’d like to use one of the free ones vs. the pay ones. I also need to be able to sell the product and receive credit card payments on the site. Thanks!