Error Message

See attach error message in the tax field.

I want to verify once the submit button is clicked, what is the email address attached to it.

I also assume that by placing their email address in the field  the customer gets a copy automatically.

Error message is shown because Validation or your field is set to Currency and a dot (.) is not accepted. You can use a comma instead of a dot for decimal places. Or you can switch Validation for your fields to Numeric. 

Once the form is submitted you will receive email Notification, to recipient email address that is set inside of Notification. 

Setting Up Email Notifications

If you want that your users also receive email when they submit the form, you need to set Autoresponder email inside of your form. 

Setting Up an Autoresponder Email

Hope this will help. Let us know if you need further assistance.