While not specifically about ecommerce, r/smallbusiness is a great place to ask questions and learn from others who are starting, owning and growing a small business.
EcomHub's official Facebook group is for high-level discussions and all things Amazon FBA & eCommerce strategies.
Richard Lazazzera of A Better Lemonade Stand runs Ecommerce Entrepreneurs. With close to 50,000 members, the Facebook group is one of the largest forums for discussion, learning, and growth on Shopify, ecommerce, digital marketing, Adwords, SEO, SEM, web analytics, content, CRM, etc.
Run by Steve Tan, this Ecommerce Facebook group is super active and busy with over 100,000 members. Discuss genera eCommerce, Shopify/Magento tips, Facebook Ads, Social Media Marketing, information about Product Sourcing, Fulfillment, Traffic and Conversion.
The DTC FAM is a small and friendly Slack group of DTC enthusiasts, started and managed by Kristen LaFrance. Join this group to talk about DTC brand marketing playbooks, what's happening in retail, celebrating wins, and generally connecting with friendly people from the DTC community.
A Facebook group focused on dropshipping and Shopify store owners hustling from France.