Hey there, celinad1979,
Thanks for visiting the Apple Support Communities. From your post, I understand that you're having trouble signing into iCloud with your Apple ID. Specifically, you've got two-factor authentication set up and need to update your trusted phone number. I'm happy to help!
Based on what you've described, I'd recommend using the steps under the "Keep your trusted phone numbers up to date" section of Two-factor authentication for Apple ID - Apple Support, which will walk you through updating your phone number online.
Cheers.