1. Slide the volume to its lowest setting. (1) Press and hold the Power Button until the system turns off (about 10 seconds). (2) Power on the system. (3) Test the volume slider to see if it adjusts the volume of the HOME menu. (4) You can use this video down here if ^^ doesn’t work. (5) https://youtu.be/zVgog-XxU2Y
You can try resetting the device putting it in recovery mode, hold down the home/power button on the side until you reach the “rebooting” screen, then let go and press the home/power button again when on the “rebooting” screen. After this, you’ll get to a page that has red text you should be able to use the home/power button to scroll down to “recovery mode” and when you’re there hold down the home/power button. This will reset your device to factory state and allow you to use your watch again.