No, all freelancers do not need a business license to operate. Some freelancers, like a freelance copywriter in Washington state, can operate under their own name as a sole proprietor. The profits from the business would be taxed as personal income.
That being said, tax law and business formation requirements can vary state by state, country by country, and also depend on which freelance profession you choose. It’s always best to review the federal requirements and local requirements regarding taxes and business formation.
That being said, there are many benefits of incorporating your business and keeping your business and personal finances seperate if and when the time is right for you.
*Note, I am not an attorney or tax professional. This advice is based on my experience in an effort to help save you some headaches in the future, supported by helpful resources. Before taking any action I would advise using a service like Law Guru to get your legal questions answered for free, search Justia to search for a local attorney, and search through your local state accountant association to find a qualified tax professional.