I received money to care for kids live-in how do I file for that

As a self-employed person you file schedule C along with your regular Form 1040.

You are self employed. You must file your tax return if yourself employed income is $400 or more. You will report your income and business related expenses on schedule C or C-EZ (Form 1040). Then you put net income (or loss) on line 12 of Form 1040. This income is subject to SE tax at 13.3% (this is shown on line 57 of Form 1040). Your U.S. Tax Return: Tax Filing by Self Employed Sole Proprietor or Independent Contractor