You are self-employed; therefore, you can reduce your income by taking authorized expenses to offset your income.
Taxes are complicate, so we can't simply give a number and tell you when you will get a refund. However, if your only income is self-employed, and you didn't pay any taxes for that income, you will not get a refund and you probably will owe taxes.
Because you are self-employed, not only will you be subject to Income Taxes, but you will also have to pay Self-Employment taxes.
The self-employment tax rate is 15.3%. That rate is the sum of 12.4% for Social Security and 2.9% for Medicare.