There are some solutions for this kind of request in Odoo. We create many solutions for our customers.But about this problem even you do not need anyone's help, you can solve this by your self.
Easiest thing to do would be to edit the email template that is being used for confirmaiton of sales. All you need to do is adding the following in the CC field if you need the Salesperson to receive a copy of the email. You can also add the Admin's email address here as well.
${object.user_id.id}
If for some reason you don't want them cc'ed on the Customer's email, you can add another automated action to send them a separate email.