If I disable my form, can I make it available/publish it again?

I have a deadline for people to apply.  How do I "turn it off" to stop accepting applications? And can I open it up again to accept new applications?

You can temporarily disable a form in Form Settings. If the form is disabled, an error message will appear when they try opening the form. Here's a guide: How-to-Enable-Disable-a-Form.

Yes, you can enable the form anytime you like.

You might want to check this helpful documentation: How-to-Limit-Submissions-in-a-Form.

Hope that helps. Let us know if you have any questions.