By default when a form is submitted the users see a generic confirmation message, you can however change this message to say anything you like, or specify a thank you page URL.
To change the thank you page settings, when you are editing the form, in the right menu you will see a "Thanks Page" button that looks like this:
When you click on this it will show options for what message you would like shown when the form has been submitted. Here you can change the text, or change the thanks page behaviour to redirect users to another URL.
You can also have "Conditional" thanks page URLs specified to dynamically alter where the form submitters are redirected to based on the values in the form.
For scenarios where you would like to pass data from the form to the thank you page, there is also a "URL Query Parameters" section where you can specify either fixed values, or values from the form submission to be passed on to the thank you page URL. This is also very useful when combined with a custom GlobalPatron thank you page, as the thank you page can use these values in its conditional logic rules to dynamically show/hide/change content depending on the scenario.