Utilize IDistributedCache for session management in .NET Core. Implement AddSession in ConfigureServices and UseSession in Configure to set up session handling effectively.

Handling sessions in .NET Core involves several steps:

1. Configure Session Middleware: Add session middleware in the Startup.cs file. This involves adding session services in the ConfigureServices method and configuring the middleware in the Configure method.

   public void ConfigureServices(IServiceCollection services)
   {
       services.AddDistributedMemoryCache();
       services.AddSession(options =>
       {
           options.IdleTimeout = TimeSpan.FromMinutes(30);
           options.Cookie.HttpOnly = true;
           options.Cookie.IsEssential = true;
       });
   }
   
   public void Configure(IApplicationBuilder app, IHostingEnvironment env)
   {
       app.UseSession();
   }

2. Store and Retrieve Data: Use the HttpContext.Session property to store and retrieve session data.

   // Store data in session
   HttpContext.Session.SetString("Key", "Value");
   
   // Retrieve data from session
   var value = HttpContext.Session.GetString("Key");

   3. Store and Retrieve Data: Use the HttpContext.Session property to store and retrieve session data.

   4. Session Security: Ensure that session data is secure by using HTTPS and setting appropriate cookie options. Avoid storing sensitive information in sessions.
   5. Session Expiration: Manage session expiration and cleanup to prevent memory leaks and ensure efficient resource usage. Configure session timeout settings based on your application’s requirements.
   6. Distributed Sessions: For applications deployed across multiple servers, use distributed session storage options like Redis or SQL Server to ensure session consistency.

Learning .NET Core can be challenging due to the vast amount of information. However, starting with C#, F#, or Visual Basic can provide a solid foundation to ease the learning process.

The difficulty of .NET Core depends on your background and experience:

1. Learning Curve: If you are new to programming or come from a non-Microsoft technology stack, there might be a learning curve. However, if you have experience with C# and the .NET Framework, transitioning to .NET Core should be relatively smooth.

2. Documentation and Community Support: .NET Core has extensive documentation and a supportive community, which can make learning easier. Microsoft provides detailed guides, tutorials, and sample projects.

3. Modern Features: .NET Core includes modern features like dependency injection, asynchronous programming, and cross-platform support, which can be challenging but also rewarding to learn.

4. Continuous Learning: Like any technology, .NET Core evolves, so continuous learning and staying updated with the latest features and best practices is essential.

5. Community and Resources: Take advantage of the vast array of resources available, including online courses, forums, and community events. Platforms like Microsoft Learn, Pluralsight, and Stack Overflow can be invaluable for learning and troubleshooting.

6. Practical Application: Apply what you learn by building projects. Practical experience is crucial for understanding how different components of .NET Core work together.

7. Mentorship and Collaboration: If possible, find a mentor or join a study group. Collaborating with others can provide new insights and make the learning process more enjoyable.