Here's a small example of deciding if a number is even or odd using the If statement in Visual Basic. For more details, please read here.
Module VBModule
Sub Main()
Dim a As Integer = 4
If a Mod 2 = 0 Then
Console.WriteLine("a is even")
Else
Console.WriteLine("a is odd")
End If
Console.WriteLine("Hello World")
End Sub
End Module
Good luck!