As you are in business - you are classified as a self-employed - your self-employment tax liability (which includes social security and Medicare taxes) is 15.3% on NET self-employment income.
and yes - that is in additional to income tax liability.On your tax return - self-employment taxes and income taxes are added together.
he net income (after deductions) will be reported on the form 1040 line 12 -
If the business has net income over $400, it may be required to file Schedule SE, Self-Employment Tax
and net self-employment income is subject to 15.3% self-employment tax.
Self-employment taxes from schedule SE will go to the form 1040 line 57 -
Also - you will deduct half of self-employment taxes on the line 27.
Generally - that all you needs tax purposes.
Please review all possible deductions - that might help to reduce income tax liability.