Usually, small businesses that are not incorporated use Schedule C to report their income and expenses.
Here's how to report Schedule C Income from self-employment in TurboTax Online:
Navigate to Federal > Wages & Income > Self-employment income and expenses > Start
Answer "Yes" to the question "Did you have any self-employment income or expenses?"
Give a description of the business
Continue until the interview asks "how does your work fit into your big picture?", based on the information you provided, it's a business.
Answer all the informational questions until you get to the screen "Let's enter the income for your work." Here, enter what you were paid.
Once you've entered your income, type in your expenses in the proper categories, TurboTax Online will recommend popular categories, but refer to your records to ensure you are deducting all of your expenses