You would report it on your Schedule C. First you would report all of your income and then list all of your expenses, so yes, you would be reporting your net earnings (after mileage, supplies, etc). You can enter that income/amount received and then begin entering your expenses by using the directions bleow.
1. Type Schedule C in the Search box at the top right of your screen and hit Enter
2. Select the Jump to blue link
You will then select "Edit" beside your business and walk through the questions until you get to the "Let's get income for XXX" screen.
You will then want to select "Additional Income" and Continue. This will take you to where you can enter any cash, personal checks or credit card payments (Form 1099-K) related to your self-employment. You may be asked some general questions about your business.
