Business owners, even part-time ones, file Schedule C of Form 1040 to document their business income and expenses.
If you have a loss (business expenses greater than business income) then it might reduce the amount of tax you owe on other income such as from being an employee or interest income.
If you have a gain (business income greater than business expenses) then you might need to pay income tax and self employment taxes on this income.
Schedule SE is used to calculate your self-employment tax. Self employment tax consists of Medicare and Social Security taxes.
If you worked for a company and received Form 1099-MISC, TurboTax will guide you through the process of completing schedules C and SE.