At most local libraries (yes they do still exist) just go to the counter and tell them you need to use a computer. If you already have a library card they will simply show you where the computers are. If you don't have a library card they will charge you a small amount to use a computer for an hour at a time.
Once logged on to the computer simply log on to Turbotax using your account information and proceed through the print process ("My Account"/"Print Center") and print your documents.
The Print Job will be sent to the Library printer. Normally there is a computer by the printer to import your Print Job.
Library printers usually charge 10 cents per page.