Apple Watch Will not turn on

Have you plugged the charger into a different outlet and tested the charging there? If you have and it still won't charge then you should take it into your local Apple Store or you can call AppleCare for assistance. AppleCare Contact Info

If you think it has some charge on it, then hold down the Digital Crown and the side button together for about 5-10 seconds and it should shutdown and then attempt to restart it.