Yes you do play an active role in your "business". You ARE the business. It's your own self employment business. The people or company that pays you is your customer or client. You need to fill out schedule C for self employment business income.
Self Employment tax (Scheduled SE) is automatically generated if a person has $400 or more of net profit from self-employment. You pay 15.3% SE tax on 92.35% of your Net Profit greater than $400. The 15.3% self employed SE Tax is to pay both the employer part and employee part of Social Security and Medicare. So you get social security credit for it when you retire. You do get to take off the 50% ER portion of the SE tax as an adjustment on 1040. The SE tax is already included in your tax due or reduced your refund. The SE tax is in addition to your regular income tax on the net profit.
Here is some IRS reading material……
IRS information on Self Employment
https://www.irs.gov/businesses/small-businesses-self-employed/self-employed-individuals-tax-center
1040 Schedule C Instructions
https://www.irs.gov/pub/irs-pdf/i1040sc.pdf
Publication 535 Business Expenses
https://www.irs.gov/pub/irs-pdf/p535.pdf
