add two window forms in your project like Form1 and Form2
make the form1 as a startup form
in Form1 load function call Form2.Show
Public Class Form1
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Form2.Show()
End Sub
End Class
in Form2 load function, add the below code to show the forms side by side. i used the form size as 300,300
Public Class Form2
Private Sub Form2_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Me.Location = New Point(Form1.Location.X + Form1.Width + 10, Form1.Location.Y)
End Sub
End Class