Hello Montana, this is Emily.
Do you have iCloud app installed on your computer? That's what you meant by One Cloud right, because I don't recall Apple has a product called One Cloud.
If you do have the iCloud app installed, you need to create an app password with Apple, and then use that app password on your computer to sign into it.
Details regarding app password can be found here: https://support.apple.com/en-us/HT204397
Note: The link above is not a Microsoft site, but it is Apple's official website.