Brand New Apple Watch Series 7 - not turning on.

Hello, Kaloy2022.

The green lightning indicator you saw tells us that the watch is charging, or charged. If your Apple Watch won't charge or you see a message on your watch that charging with this accessory isn't supported: 

1. Make sure that you plug the Apple Magnetic Charging Cable or USB-C Magnetic Fast Charging Cable all the way into the USB Power Adapter, then make sure that you plug the adapter all the way into a power outlet.
2. Make sure that you're using the Apple Magnetic Charging Cable or USB-C Magnetic Fast Charging Cable that came with your Apple Watch. 
3. Completely remove any plastic wrap from both sides of the charger. 
4. Make sure that the back of your Apple Watch and the magnetic charger are clean.
5. Position the back of your Apple Watch on the charger. The charger's magnets align your Apple Watch, and you should see a green lightning bolt on the watch face.
6. If your Apple Watch still won't charge, force it to restart. Press and hold both the side button and Digital Crown for at least 10 seconds, or until you see the Apple logo.
7. Try a different Apple Watch Magnetic Charging Cable or USB-C Magnetic Fast Charging Cable, and a different USB Power Adapter. If your Apple Watch is out of power, you might need to wait a few minutes for the green lightning bolt to appear after you start charging your device. 

These steps and other tips are provided here: If your Apple Watch won't charge or it won't turn on - Apple Support.

Let us know if we can help with anything else at all or if this doesn't settle your issue. Thanks and have a fabulous day!