To get a copy of your 2018 tax return that you filed this year, sign back in to your account and either:
Your printout will include extra documentation and calculation worksheets for your files but not W-2s, 1099s, or any other forms from your employer, bank, brokerage etc. because TurboTax didn't generate those forms.
For more information on related topics, such as trouble accessing your TurboTax account, have a look under Related Information.