Different usage of Aync in C#

AsyncSample.cs

 public class MegaClass
    {
        public async void StartAsync()
        {
            await Task.Run(() => { LongProcedure(); });
            Console.WriteLine("End");
        }

        public void Start()
        {
            LongProcedure();
            Console.WriteLine("End");
        }

        private void LongProcedure()
        {
            Thread.Sleep(3000);
        }

        public async Task MyMethodAsync()
        {
            int x = await LongRunningOperationAsync();
            Console.WriteLine(x);
        }


        public async Task<int> LongRunningOperationAsync() 
        {
            await Task.Delay(3000); 
            return 1;
        }

        public async Task<int> LongRunningOperationAsync(int _param)
        {
            await Task.Delay(3000);
            return _param;
        }

    }

    class Program
    {
        static void Main(string[] args)
        {
            var _c = new MegaClass();

            //1 Sync
            //_c.Start();

            //2 Async
            //c.StartAsync();

            //3 Start and return task
            //Task t = _c.MyMethodAsync();
            //t.Wait();

            //4
            //Task task = new Task(_c.StartAsync);
            //task.Start();

            //5 GetResult <int>
            //Task<int> x = _c.LongRunningOperationAsync();
            //x.Wait();
            //Console.WriteLine(x.Result);

            //6 with param
            //Task<int> x = _c.LongRunningOperationAsync(3);
            //x.Wait();
            //Console.WriteLine(x.Result);

            Console.WriteLine("Wait");
            Console.ReadLine();
        }
    }