I hesitated to reply with solution for your questions from your comments, since you really should do your homework first. You need to study a little on your own.
But anyway here it goes your solution:
private void dateTimePicker1_ValueChanged(object sender, EventArgs e)
{
dateTimePicker2.MinDate = dateTimePicker1.Value;
}
But please try to learn some basics first. This way you will not face problem in every other line of the code you are trying to write. Good luck with it:)