Write (Save) Console Application output in Notepad using C#

I created a registration form in console application and output in notepad.

But the code is not standardised. How to make it ?

The output is perfect but code.

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int partner = 0;
            FileStream ostrm;
            StreamWriter writer;
            TextWriter oldout = Console.Out;
            string codex = "";
            string code1x = "";
            string code2x = "";
            string code21x = "";
            string code3x = "";
            int key;
            string first = "Enter First Name";
            string second = "Enter surName";
            string third = "Enter Date Of Birth,(dd/MM/yyyy)";
            string fourth = "Enter Martial Status(s/m)";
            String five = "Age";
            Console.WriteLine(first);
            Console.WriteLine(" ");
            string code = Console.ReadLine();
            Console.WriteLine(second);
            string code1 = Console.ReadLine();
            Console.WriteLine(third);
            string code2 = Console.ReadLine();
            DateTime dob = Convert.ToDateTime(code2);
            string code21 = Console.ReadLine();
            Console.WriteLine(CalculateYourAge(dob));
            string Age = CalculateYourAge(dob);
            int ageyr = int.Parse(Age.ToString());
            Console.WriteLine(fourth);
            string singleormarried = Console.ReadLine();

            string code3 = Console.ReadLine();
            Console.WriteLine();

            if (ageyr < 18)
            {
                Console.WriteLine("Parent Autorisation Needed,do you?(y/n");
                string authorisation = Console.ReadLine();
                if ((authorisation == "n") || (authorisation == "N"))
                {
                    Console.Write("Access Denied");
                    string remark = Console.ReadLine();
                }
            }
            if((singleormarried=="m"))
            {
                partner = 1;
                string pfirst = "Enter Partner's First Name";
                string psecond = "Enter surName";
                string pthird = "Enter Date Of Birth,(dd/MM/yyyy)";
            
                Console.WriteLine(pfirst);
                Console.WriteLine(" ");
                codex = Console.ReadLine();
                Console.WriteLine(psecond);
                code1x = Console.ReadLine();
                Console.WriteLine(pthird);
                code2x = Console.ReadLine();
                DateTime dobx = Convert.ToDateTime(code2x);
                code21x = Console.ReadLine();
                Console.WriteLine(CalculateYourAge(dobx));
                string Agex = CalculateYourAge(dobx);

                int ageyrx = int.Parse(Age.ToString());
             
                Console.WriteLine();
            }
                string line = first + "  " + code;
                string line1 = second + "  " + code1;
                string line2 = third + "  " + code2;
                string age = five+" "+Age;
                string line3 = fourth + "  " + code3;



                string linex = first + "  " + codex;
                string line1x = second + "  " + code1x;
                string line2x = third + "  " + code2x;


                string s = "***********************   Registration Form ************************" + Environment.NewLine + Environment.NewLine + line + Environment.NewLine + Environment.NewLine + line1 + Environment.NewLine + Environment.NewLine + line2  +Environment.NewLine+Environment.NewLine + age +  Environment.NewLine +Environment.NewLine + line3;
                string s1 = "";
                if (partner == 1)
                {
                    s1 = Environment.NewLine + Environment.NewLine + "***********************   Partner's Name ************************" + Environment.NewLine + Environment.NewLine + linex + Environment.NewLine + Environment.NewLine + line1x + Environment.NewLine + Environment.NewLine + line2x;
                }
                else
                {
                    s1 = "";
                }
                string s2 = s + s1;
                FileStream filestream = new FileStream("D:\\people.txt", FileMode.Create);
                StreamReader sr = new StreamReader(filestream);
                sr.Close();
                System.IO.File.WriteAllText("D:\\people.txt", s2);
        }
        public static string CalculateYourAge(DateTime dob)
        {
            var now = DateTime.Now;
            var years = new DateTime(DateTime.Now.Subtract(dob).Ticks).Year - 1;
            var pastYearDate = dob.AddYears(years);
            var months = 0;
            for (var i = 1; i <= 12; i++)
            {
                if (pastYearDate.AddMonths(i) == now)
                {
                    months = i;
                    break;
                }

                if (pastYearDate.AddMonths(i) < now)
                    continue;
                months = i - 1;
                break;
            }

            var days = now.Subtract(pastYearDate.AddMonths(months)).Days;
            var hours = now.Subtract(pastYearDate).Hours;
            var seconds = now.Subtract(pastYearDate).Seconds;
            return string.Format("{0}", years);
            // return string.Format("Age: {0} Year(s) {1} Month(s) {2} Day(s) {3} Hour(s) {4} Second(s)", years, months, days, hours, seconds);
        }
    }
}