If his income was reported on a 1099NEC, he has self-employment income, which is treated as if he was an independent contractor. He will owe self-employment tax for Social Security and Medicare.
You will need to use online Premium software or any version of the CD/download so that you can prepare a Schedule C for your business expenses.
https://ttlc.intuit.com/questions/2926899-how-does-my-side-job-affect-my-taxes
https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/00/25922
https://ttlc.intuit.com/questions/2902389-why-am-i-paying-self-employment-tax
https://ttlc.intuit.com/questions/1901340-where-do-i-enter-schedule-c
https://ttlc.intuit.com/questions/3398950-what-self-employed-expenses-can-i-deduct
https://blog.turbotax.intuit.com/self-employed/self-employed-tax-deductions-
calculator-2021-2022-50907/
https://ttlc.intuit.com/questions/1901110-do-i-need-to-make-estimated-tax-payments-to-the-irs
https://turbotax.intuit.com/tax-tools/calculators/self-employed/
Or—-Use this IRS site for other ways to file for free. There are 8 free software versions available from the IRS Free File site
https://apps.irs.gov/app/freeFile/