In this blog post, it is shown how to use the IfError function to create professional, dynamic, user-friendly, and informative error messages when using the Edit Form control for your data entry functions in the Canvas PowerApps.
Find the IfError function reference here, to learn more about the usage of this PowerFx Function: IfError function reference.
Get an overview of possible error kinds and how the Errors function behaves here: Errors Function / Error Kinds.