How did you find your first few customers?

If you're referring to the very first customers, they usually come from people we know, who then recommend the product to others in their network, and so on :)

From social media.

If you're referring to random strangers online, I did it by writing tutorial articles on Medium or Hackernoon about the problem I was trying to solve and providing initial guidance on how they could do it themselves. Only then would I subtly promote my project at the end of the article, explaining how it could save them time by using the project directly.