TurboTax does not mail your return for you.  You have to print it, sign it, and mail it yourself.  When you mail a tax return, you need to sign it on the bottom of the page where it says "Sign Here" and write in the date you signed it by the word "Date".  Attach copies of your W-2 and any other documents that show taxes withheld to the left side of the papers where it says "Attach Forms..."

When you print your return, it will print with filing instructions that tell you where to mail it.

It is not required, but is a good idea, to use a mailing service that will track your return or provide you with a receipt showing that the IRS got it--such as Fedex, UPS, or certified mail.

It will take about 4 weeks and then you can track the status of your return at the IRS website.

You can print your return by following the instructions below 

(Note:  Before you can print, your TurboTax fees must be paid)

https://ttlc.intuit.com/questions/1944348-how-do-i-print-and-mail-my-return-in-turbotax-online

To send your tax return by mail and get a receipt to see that the IRS received it:

https://www.usps.com/taxes/welcome.htm

To track your Federal refund:   

https://www.irs.gov/refunds

To track your state refund:    

https://ttlc.intuit.com/questions/1899433

On the IRS site you are also offered the use of an app called IRS2Go

If you want to switch from mailing to e-file:

https://ttlc.intuit.com/questions/2403338-how-do-i-change-from-mail-to-e-file?jump_to=answer_3985787