C# Web ASP .NET Core

I am a student, and I have some issues with an already written project on ASP .NET Core MVC that Runs via Docker, with which I need some help. I have created my database and inserted some data. Also, I got a view (web pages). Project Details: Art Gallery's main idea is to be an app for booking and sales. A place where regular users can book an exhibition or buy a painting. three roles: user, admin and manager. User: * Can book an exhibition event in the Gallery or buy a painting from the app store. * Can read Blog Posts and create comments on any Article. * Cancel booked exhibition events or request orders cancellation. Once a User cancels, the manager should approve an already made order. Admin: * Can create or delete Blog Posts. * Can create, update or delete events and paintings available for sale. * Can Manage Users. Restrictions: * Guest Vistors (a user who is not logged in) are restricted to browsing through exhibition events and painting in the App Store and the Blog Posts, which are available for them to read. * Users are not allowed to create Blog Posts, Events or new Arts for purchases only if they are Administrators. * Any user can create Comments as long as it is a Logged-in user. * Only Guest visitors cannot create comments, make orders or book events. * Only admin is allowed to create Blog Posts, Events. Problems that I got with my project: - When I run my project, the Browser is showing my project visually, but on my web pages, I receive different errors. The last error is NullReferencesException instead of my Views which are already created. - Database issues: I got a Connection to the SQL Server and the database was created with some inserted data, but I have a problem extracting the data. It doesn't show in the Browers. - The Identity in the Web did not log me in automatically as it was supposed to. I need to log in as an Administrator, which my project is not able to do at the moment, to be able to change data in the database. Also, I need help doing some Testing for the Services folder in ArtGallery.Core. Get in touch with me for more details.