Use a micro USB 2.0 cable to connect the nRF5340 DK to one of your PC's USB host ports. This provides power to the board and supports target programming.
If you plan to use NFC, connect the NFC antenna to the board. The connector is marked "NFC" and located on the edge of the board near the 4 buttons.
Flip the power switch to "on". Find it near the micro USB connector. If a popup appears, ignore it for now.
Confirm that LED 1 has started pulsating.
Use buttons 1 to 4 to control which LED is pulsating.