As per my understanding you are creating pages for 2nd and 3rd level, So I think those pages will be stored on your site somewhere in Site Pages, Pages or Site Assets library.
For Example: My page URL is
https://domain.sharepoint.com/sites/sitename/SitePages/Page1.aspx then this page with name
Page1.aspx is stored in Site Pages library (Which you can see from Site Contents page).
If users are not able to access those pages then you need to check the permissions for that particular library. You can check the permissions on list/library from List/Library settings.
In order to see the pages, user should have at least Read permission.
Customize permissions for a SharePoint list or library.
Understanding permission levels in SharePoint.
Note: Also make sure that user is having permission on the Microsoft form or you need to share your form with the users you are targeting. Check the reference, Send a form and collect responses.