How do new startups actually find their first clients? "I will not promote"

I recently started my own business offering penetration testing and AI-related services/products. The company is established, and I have the technical people and skills available, but I’m finding that the hardest part is actually getting clients. I’ve tried cold outreach, but I rarely get responses. I’m not sure if it’s because the company is new, there isn’t enough trust yet, or because cold outreach simply comes across as spam. What I don’t understand is how other new startups manage to get their first clients, especially when some of them already have physical offices and employees. From my perspective, getting those first few customers seems extremely difficult. For those who have started a business, especially in cybersecurity, IT, consulting, or AI, how did you find your first clients? Did you use: Cold outreach LinkedIn Referrals/networking Partnerships Freelance platforms Paid advertising Local businesses Conferences/events Something else? Any advice, strategies, or lessons from your experience would be greatly appreciated.