If you haven't registered your one-person (independent contracting) business as any other legal entity, such as an LLC, corporation, or S corporation, your business is considered by the IRS to be a sole proprietorship (i.e. you are the owner of your independent contracting) business by default. See here for some more details.

No "percentage"---if you received earnings as an independent contractor the IRS sees you as self-employed even if you were paid in cash, received a 1099NEC, and/or did not have business name, license, etc,

https://ttlc.intuit.com/questions/2903027-how-do-i-report-income-from-self-employment

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

If your self-employment income was only from cash, personal checks, credit card payments, or cryptocurrency 

Type Schedule C in the Search box and then select the Jump to link. This will take you to where you can enter any cash, personal checks, credit card payments, or cryptocurrency (Form 1099-K) related to your self-employment. You may first be asked some general questions about your business. After you answer them, you’ll be taken to the Let's get income for (your line of work) screen where you can enter this income as Additional Income.