How can I send a confirmation email to customers?

How can I set a form to send a confirmation of the person's order once the form is submitted?

You can make an autoresponder email that delivers form inputs to the user through the email.

To do so follow the next steps:

First, go to your form's settings tab. Then under the email tab create a new autoresponder email like this:

Secondly, you can configure said email option to send out only the information you want the user to receive in the confirmation email like this:

Note: 

The email content updates automatically with the input fields you have on your form, but you can delete the lines you don't want the user to receive. 

Hope this helps!