Yes, you have to file taxes on that activity.
The self employed are expected to report their income and expenses based on their own accounting records. The purpose of forms like W-2, 1099-K and 1099-Misc is to make sure the IRS knows about as much of your income as reasonably possible.
Even if you consider this a hobby, and not a business, there are tax reporting requirements.
https://www.irs.gov/uac/business-or-hobby-answer-has-implications-for-deductions
