It said I needed a specific form that had to be signed and snail-mailed for the state of Pennsylvania but then it never gave me the form - what form is this?

You should be able to find the mailing instructions by following the instructions below:

Please log back in your TurboTax account and "add a state" to open the return back up (you are not really adding a state, just to open it back up), then select Tools on the left, Print Center and choose the print center, then select returns and choose to print just the tax return or to include all worksheets as well.