Business & farm

Yes, you do need to enter your business income and expenses on a Schedule C. When you enter your Form 1099-K there is a screen that says What type of income is your 1099-K for? To which you need to respond Self-employment income. Later in that section you will see a screen that says Your self-employment 1099-K income where you can select the Schedule C you have already set up, or you can set up a new one:

After you enter the Form 1099-K, go to the self-employment income section and enter your business expenses.