I'll assume you mean your new watch is asking you to sign into your Apple ID. As others have said, your message is pretty vague.
If that's the case, you'll just have to type in your Apple ID password. If you're having trouble typing it out on the watch (because how would you type a complex password on your watch), you can sort of just hold up your watch near your phone when you open the keyboard and it will sometimes rarely let you input text with your iPhone's keyboard. That's what I had to do to get it to actually put in my password right.