It depends on what you do. B2C? B2B? SaaS? Ecommerce? At the beginning, the idea is to "do things that don't scale": do things manually, go get your users one

It depends on what you do. B2C? B2B? SaaS? Ecommerce? At the beginning, the idea is to "do things that don't scale": do things manually, go get your users one by one. At the same time experiment with traction channels: SEO, content marketing, social media, email, PR, email marketing, outbound sales. Do small experiments and do more of what works.