First you deduct expenses from what you made to find your adjusted income. Next you follow the formula to figure out how much social security (self employment tax) you owe. I can tell you that after you get the amount you owe SS on, you will have to pay the whole amount not just 1/2 like emotes do. Then you can deduct 1/2 of the SS you paid from your adjusted gross and that will give you how much income tax you owe in addition to the SS. You can possibly get a refund under earned income credit if you qualify.
You are supposed to pay 10% on taxable income if you earn from $0 to $8,700. This means you should aggregate your total income and tax it at 10%, which you should remit to the IRS. A tax refund is only given if you paid more tax than you should have, so unless you pay more than you are supposed to, you won't be getting any refund.