How do I unlock my Apple Watch w my iCloud account

If you have forgotten your apple id password you first need to recover it

Reset your Apple ID password on your iPhone or other trusted Apple device

1. Go to Settings.
2. Tap your name > Password & Security > Change Password.
3. Follow the onscreen instructions to reset your password.

You can also follow this process on a trusted iPad, iPod touch or Apple Watch.

To reset your password on your trusted Mac, choose Apple menu  > System Settings (or System Preferences) > Sign in with your Apple ID (or Apple ID). Then click Password & Security, Change Password and follow the onscreen instructions.

If you don't have a trusted device, follow these steps instead

If you don't have an Apple device but have access to your trusted phone number, you can borrow an Apple device from a friend or family member, or use one at an Apple Store.

1. Open the Apple Support app on the borrowed Apple device. If necessary, you can download the Apple Support app from the App Store.
2. Scroll down to Support Tools, then tap Reset Password.
3. Tap "A different Apple ID".
4. Enter your Apple ID, tap Next and follow the onscreen instructions to reset your password.

If you cannot reset your password via a device you can also try it on the web

If you don't have a trusted device, you can reset your password on the web – but the process may take a little longer.

When possible, the web browser will redirect you to a trusted device. If you'll have access to one of your trusted devices soon, it may be faster and easier to reset your password then.

Reset your password at iforgot.apple.com

If you cannot reset your password at any of these methods you might want to enroll in account recovery to regain access to your Apple ID in order to remove the activation lock from the Apple Watch

How to use account recovery when you can’t reset your Apple ID password - Apple Support