Creating

Windows Forms App (.NET Framework)

uses .NET Framework 4.7.2

Windows Forms App

uses .NET 6.0

Using Constructor

public partial class MyForm : System.Windows.Forms.Form 
{ 
  public MyForm() 
  { 
    InitializeComponent(); 
    this.Text = "Form Title"; 
  } 
} 

Using the Load Event

This is a windows form Built-in event

public partial class Form1 : System.Windows.Forms.Form 
{ 
  private void Form1_Load(object sender, 
                          EventArgs e) 
  { 
    this.Text = "Form Title"; 
  } 
}