Health Insurance -- Moving from NL to Germany (Berlin)

Hello,
I am a US passport holder. I lived and worked in Netherlands for 9 years and I have NL permanent residency card with EU long duration status and I have health insurance coverage from Netherlands. I am moving to Berlin soon and I want to be Berlin resident. Looks like German health insurance system quite complex compared to NL. I am looking for basic coverage (emergency+primary care ). Must I be employed to get health insurance? Can I get insurance provided by the government? Is there a website that explains the plans and options?

Thanks in advance.