Do you have to be a lawyer or attend law school to be a Supreme Court Justice? The Constitution does not specify qualifications for Justices such as age, education, profession, or native-born citizenship. A Justice does not have to be a lawyer or a law school graduate, but all Justices have been trained in the law.
https://www.supremecourt.gov/about/faq_general.aspx#:~:text=Do%20you%20have%20to%20be,been%20trained%20in%20the%20law.