Your first customers should be your easiest. Startups don't really have time to chase every lead. You can pick only the ones that are the most likely close. Avoid those who are moving slow and don't be afraid of letting customers go.
How do you get your first customers? YC Group Partner & former Head of Growth at Airbnb, Gustaf Alströmer, gives tactical advice to answer this question for all kinds of companies — whether you're B2B or B2C — and discusses why it's important for founders to do sales early on. Apply to Y Combinator: https://yc.link/SUS-apply