If/or when you closed TTax, it should've asked you "Do you want to save?" I hope you did. Then, open TTax again, and your return should be there on the page to click and open. If you have worked on more than one return, you'll see more than one option of returns available to open, if you don't recognize the "name" open each one and see.
If you still have TTax open, it may be there in front of you, but hidden on the start bar. If you happen to be working on a different return, go to the upper left corner of the TTax page, you'll see: 'File,' 'Edit,' etc.. Click on File, 2nd choice down: click on "Open Tax Return" (it'll ask you if you want to save the return you're working on, click yes.) The TTax intro page should come up with a choice of however many returns you've been working on.
You may have a PDF file saved on the computer in Documents or wherever you like to save things.