How to implement and is this application design correct?

Question

.NET

Good afternoon. Tell me please. I want to create an application using wpf with the following layout: I

plan to store the content in pages.
This raises several questions.
Is it correct to use frames to solve such a problem?
Yesterday I tried the layout and failed to load a page with text into the HelpFrame frame after switching to another page in the MainFrame frame. The error is that the HelpFrame is not located on another page, so the NavigateTo method cannot be used.
I will be glad for any help. Thank you.