To shop owners that advertise little to none and rely on natural growth and SEO, how did you start?

I’m looking to start a store off of mostly natural growth such as SEO, but I don’t know how to get off of my feet. I feel like it’s very difficult for a new shop to get natural growth which is why I’m here asking you guys. Did you start with ads and switch to none, advertise very little, etc.? Any help would be heavily appreciated, or just explain yourself as far as you’re willing to.