Signing Apple Watch in to iCloud

1.I am suddenly unable to unlock my iMac using Apple Watch. I am instructed the AW must be signed in to iCloud t unlock. I am advised that I can sign using the AW app on my iPhone 13. But after two days slaving at this I cannot do it, even though I have been happily using the unlock facility for months. It may be my age (77) but I just cannot make head or tail of this.

1. I live by alarms (medicines). All of a sudden I get the USUAL message of SNOOZE or STOP plus a strange on screen message DOUBLE CLENCH. What is this? How do I get rid of it.

Any help with above issues greatly appreciated.

Thank you,

Pat