Some of the widely used eCommerce themes for WordPress are Jayla,eLab, Hongo, Merchandiser, etc.

But Flatsome is also a good choice. It has over 7500 sales as people find it right for their websites.

Some other options like “Better- A business word press theme” is decent and does not have a lot of bells and whistles.

Finally, the best way is to choose a free theme. Because you can test whether a free theme is going to work for your store in WordPress/Woocommerce. However, if you do not find it useful, you can switch over to some other eCommerce platforms like Magento, Shopify, etc.