If your income was reported on a W-2 which shows that Federal tax, Social Security tax, Medicare tax, and state income tax was withheld from your income, then you do not need a Schedule C.
However, if there is a box checked on your W-2 that indicates you are a statutory employee, then you will need a Schedule C included as part of your tax return to report your income, regardless of whether you have any expenses to claim.
See the following TurboTax help article to learn more:
What's a statutory employee?