I'm trying to print out my 2019 tax return and it doesn't give me an option to print, only save. How do I print it out to mail?

Did you use the CD/download to prepare your 2019 return?   You should be able to go up to the tool bar on your computer and click File and then click Print from the drop down menu.   Or when in the File section of the software you can choose to print and file by mail.   

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.

See this:

How do I view, download, or print a prior-year tax return? (intuit.com)