Your tax return will be Pending until the IRS starts accepts the return. Usually this takes 24 - 48 hours however it can stay in pending status for a week or 2 depending on what is happening with the IRS at certain times of the year so just be patient.
You will receive an email from TurboTax when the tax return has either been accepted or rejected. After the tax return has been Accepted by the IRS (meaning only that they received the return) it will be in the Processing mode until the tax refund has been Approved and then an Issue Date will be available on the IRS website -
Use this TurboTax website to check the status of an e-filed return and if it was either accepted or rejected -
https://turbotax.intuit.com/tax-tools/efile-status-lookup/If accepted by the IRS use the federal tax refund website to check the refund status -
https://www.irs.gov/refundsIf accepted by the state use this TurboTax support FAQ to check the state tax refund status -
https://ttlc.intuit.com/questions/1899433-how-do-i-track-my-state-refund