Car Database Loop

this code doesn't seem to be working. I don't really know what loop to use to get it too add the information the user puts into the machine to print again. The aim of this is for the user to either pick 1) to print a menu that they have typed in an earlier database. If they haven't typed anything into the database, then it should be blank, 2) Should let the user enter ifnormation into the databse (What I am mostly strugglign with) and do error checking so that it tells them if they have entered a number when they shoiuld have entereed a letter and 3) To end the program. When I do 2) It lets me type but it doesnt recall the infomation back in the database. Also it needs a number 4) which should return to the main menu. Which i think is where the loops come in but i dont know which one to use Here is the code:

Structure Cars

Public carmake As String

Public carmodel As String

Public caryear As Integer

Public carlicence As String

End Structure Module Module1

Sub Main()
    Dim userchoice
    Console.WriteLine("Choose weather to open the database(1), print it (2) or end (3)")
    userchoice = Console.ReadLine()
    If userchoice = 1 Then
        Dim cardatabase(4) As Cars

        Console.WriteLine("This will allow you to view the database.")
        Console.WriteLine("Please enter the car make,licence,model and year")
        cardatabase(1).carmake = Console.ReadLine()
        cardatabase(1).carlicence = Console.ReadLine()
        cardatabase(1).carmodel = Console.ReadLine()
        cardatabase(1).caryear = Console.ReadLine()
    ElseIf userchoice = 2 Then
        Console.WriteLine("The database is,")
    ElseIf userchoice = 3 Then
        Console.WriteLine("Thanks for using this program.")
    End If
    Console.ReadLine()
End Sub