Hi, did you read the dev kit user guide and follow below steps? If yes, might need check if any log output.
Before using your developer kit, you need to set up a microSD card with the operating system and JetPack components. The simplest method is to download the microSD card image and follow instructions found in Getting Started with Jetson Nano Developer Kit.
• You need a 16 GB or larger UHS-1 microSD card, HDMI or DP monitor, USB keyboard and mouse, and 5V⎓2A Micro-USB power supply.
• Download the image and write it to the microSD card.
• Insert the microSD card into the slot under the Jetson Nano module, then attach the display, keyboard, mouse, and Ethernet cable or wireless networking adapter.
• Connect the Micro-USB power supply. The developer kit powers on automatically.
For alternative methods, see How to Install JetPack, below.