How can I view how the visitor who filled my form got to my site?

is there a referral on how my visitors get to my site?  say the saw it on an ad, of via google , etc etc

You can try to check the Get Referrer widget. This would allow you to see where your form was accessed first before it was loaded.

On the submission page, it would show like this: 

It shows www.facebook.com on my submission page since the form is added as a link on my Facebook page.

I hope this helps. Let us know if you need any further assistance. Thank you.