Good afternoon Motolady2001,
Welcome to the Apple Support Communities!
I understand you are being prompted to "sign in to iCloud" every day on your Apple Watch Series 1. What iPhone are you pairing this Apple Watch with? Has it been updated to iOS 13.3?
Update your iPhone, iPad, or iPod touch
Update your Apple Watch
"watchOS 6 is compatible with Apple Watch Series 1 and later. Upgrading to watchOS 6 requires an iPhone 6s or later running iOS 13 or later. Find your Apple Watch model."
Most people use the same Apple ID (usually their primary email address) for their iTunes & App Store purchases and for their iCloud data and backups. It sounds like this is the case for you since the password worked.
If your iPhone is updated to iOS 13.3, check your iCloud settings on your iPhone. If you are signed in to iCloud on your iPhone, you shouldn't be prompted to sign in on the Apple Watch that is paired to it. Restart your iPhone after changing any settings to refresh it and reestablish a connection to the internet. Then restart your Apple Watch.
Manage Apple ID and iCloud settings on iPhone - iPhone User Guide
How to restart your Apple Watch
You can reset the passcode for your Apple Watch if you wish. Be sure to write down your passwords and passcodes for your devices and keep this information in a safe place.
Reset the passcode on your Apple Watch
If the issue persists after making these updates, you may need to unpair your Apple Watch and pair it again to your iPhone.
Unpair and erase your Apple Watch
Please reply to this thread if you are still getting prompts to sign in to iCloud on your Apple Watch after making these changes.
Enjoy your day!