Can I limit the number of responses to a survey?

If I am using a form as an event sign up, is there a way to limit form responses when it reaches a certain number of it? Also, if so, is there a way to customize the message (ex. Thank you for your interest but we are all full. etc)

It is indeed possible to limit the number of submissions through the forms.  Here is our guide on how to do so:

https://www.jotform.com/help/137-How-to-Limit-Submissions-in-a-Form

The message shown when the form is disabled can be customized.