If you're the only owner of the LLC, and you didn't file and election to treat the LLC as a separate tax entity, you'll report your business income and deductions in TurboTax on Schedule C. If your business had no income or expenses last year, there's nothing for you to report on your federal tax return.
You may have separate filing requirements with your state's department of revenue or secretary of state's office. I suggest checking the websites for those offices for more information.