If you had no income at all you do not have to file a tax return unless you received advance premium tax credit for health insurance from the Marketplace ("Obamacare"), or you took money out of a Health Savings Account (HSA) or Medical Savings Account (MSA).
TurboTax sends reminders because it sees that you have a TurboTax account but you haven't filed. It has no way of knowing that you had no income. You can just ignore the reminders.
