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.
Run by Jonathan Kennedy of HeyCarson, Shopify Entrepreneurs is one the largest and most active ecommerce communities on the internet. With over 100,000 members, join this community to talk about all things ecommerce across every kind of topic.
Alex Fedotoff runs a Facebook group with nearly 50,000 members dedicated to intermediate-advanced Facebook advertisers and eCommerce entrepreneurs, who are spending $5,000 - $1,000,000+ per month on ads. If that's you, this might be the right place to pose problems and learn from marketers.
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.
Run by Sugatan, this group is designed for people who already have eCommerce businesses and who want to optimize and grow quickly. Learn about Facebook Advertising, Website Performance Optimization (CRO), Marketing Strategies, Native Ads, Store optimization, Email Marketing and more.
EcomHunt is a curation of the best new products, every day. Discuss winning products to sell via your online store.