Sending an email to the respondent upon form submission is a very common need, luckily it's very easy to set up.
Before we begin: You must have an "Email" question in your form before you can set this up.
-
In the form editor, go to After Submission → Emails and press the "Add Email +" button.
-
In the "To" field, choose the email question from the form that you expect the respondent to put their email address in.

-
Fill out the rest of the email setup to specify what the contents of the email should be (e.g. subject line, attachments, and messaging).
-
When you're ready, click "Add Email".
-
Publish and view your form, then run a test submission with your email address to receive the email.