My Apple Watch won’t work

Hi, i got an Apple Watch today and I went to set it up just and I’m writing in my Apple id and password and it’s saying it won’t work because the watch is set up with a different Apple ID email which isn’t mine and I have no idea what the password is. How can I completely wipe the watch and start all over again? Or is there any other tips you can give me? Every time I restart it it just says the same