How to send acknowledgement to users when form is submitted?

I want that every user filling the form should be able to get acknowledgement of the same over his email. Please help on the same.

If you want to send email to your users, when they submit your form, you need to set up Autoresponder email inside of your form.

Inside of this guide you can find how to do it:

Setting Up an Autoresponder Email

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