Why my 2018 tax return is only 3 pages long?

If you downloaded the PDF from the Tax Home web page, then you will only receive the tax return as was sent to the IRS, not any of the worksheets.

When you sign onto your online account and land on the Tax Home web page, scroll down and click on Add a state.  See screenshot

 This will take you back to the 2018 online tax return.

I’m trying to figure out that this year. 

The 1040 is just a two-page form and then you may have one or more of the attached schedules.

• Down the left hand side, click on Tax Tools.
• Click on Print Center.
• Click on Print, save or preview this year’s return.
• To see all of the attachments prepared by the software, choose the option Include government and TurboTax worksheets.

See this TurboTax help.