Hello @zenaone thank you for this question, great one!
Generally, you would not have a filing requirement for income tax purposes if your total income is below the standard deduction amount. However, since you are self-employed, your net income from self-employment activities are subject to FICA taxes (Social Security, Medicare, etc.) which would require you to file a tax return. I would suggest filing a tax return to compute your FICA taxes, even though you may not be subject to income taxes.
The IRS has a wonderful tool for you to determine your filing requirement, you can check that out here.