Assuming you have a simple business, such as rental income, Uber driver income, and etc.
1. File F1040 and all others that you usually should file, plus
2. File Schedule C - Profit or Loss From Business (assuming you have profits)
3. File Schedule SE - Self-Employment Tax (In general, if you owe $1000 or more tax on F1040, be sure to pay estimated tax each quoter to avoid penality. You can do this online.)
4. File Schedule 1-5, whichever are required. Then refine Form 1040.
* The amount on 3 (Self-Employment Tax) will be counted towards your social security benifit/Medicare. I would suggest you use a tax software to make life easier.
