When online TurboTx opens for 2019 returns on December 4, you will also be able to purchase PLUS in order to access your old tax returns.
You can get a free transcript from the IRS:
How do I get a copy of a return I filed using online TurboTax?
How do I get a copy of a return I prepared using desktop TurboTax?
You say you want to use your 2017 return as a "guide" for a new tax return. Do be aware that the tax forms and tax laws changed drastically for 2018 and beyond. The Form 1040 is very different for 2018 from what it looked like for a 2017 return, and the forms are changing again for 2019.