Hello there, @Peggycoolmom ...
It sounds like you might want to utilize the Canvas Parent app on your phone. I'm not sure what kind of phone you have, but here are links to all of the Guides for both Android and iOS devices:
Hopefully, you will be able to find the relevant Guide(s) to help your child's account linked correctly on your mobile device. Please let Community members know if you have any other questions about this...thanks!
