How do I read and write from a file?

Console.WriteLine("________________Student information______________");
                   Console.WriteLine("Enter student name ");
                   Firstname = Console.ReadLine();
                   Console.WriteLine("Enter the Surname ");
                   Surname = Console.ReadLine();
                   Console.WriteLine("Enter student date of birth");
                   DOB = DateTime.Parse(Console.ReadLine());
                   Console.WriteLine("Enter student Gender either F/M ");
                   Gender = char.Parse(Console.ReadLine());
                   Console.WriteLine("Total fees paid N$");
                   Total_Fees_paid = double.Parse(Console.ReadLine());
                   amount_owed = totalcost - Total_Fees_paid;
                   Console.WriteLine("__________NEXT OF KIN__________");
                   Console.WriteLine("Enter next of kin/parent/gurdian's Title ");
                   nTitle = Console.ReadLine();
                   Console.WriteLine("Enter next of kin/parent/gurdian's Name ");
                   nFirstname = Console.ReadLine();
                   Console.WriteLine("Enter next of kin/parent/gurdian's Surname ");
                   nsurname = Console.ReadLine();
                   Console.WriteLine("Enter next of kin/parent/gurdian's date of birth");
                   nDOB = DateTime.Parse(Console.ReadLine());
                   Console.WriteLine("Enter next of kin/parent/gurdian's Occupation");
                   nOccupation = Console.ReadLine();
                   Console.WriteLine("Enter next of kin/parent/gurdian's Desgnation");
                   nDesgination = Console.ReadLine();