how to set time to close form

hello! I started to do the alphabet for my daughter and would like to set the time on the form that when it opens it closes itself after 30 seconds. I tried everything I even looked for solutions in the forum but whenever I enter the code you find you do not get nothing but mistakes .... This is my code so if someone can help me thank him.

Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        A.Show()
        My.Computer.Audio.Play("D:\Abeceda\zvuk/a.wav")

    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

        B.Show()
        My.Computer.Audio.Play("D:\Abeceda\zvuk/b.wav")

    End Sub

End Class