There are nine supreme court justices

Back row (left to right): Brett Kavanaugh, Elena Kagan, Neil Gorsuch, Amy Coney Barrett.

Front row (left to right): Samuel Alito, Clarence Thomas, Chief Justice John Roberts, Stephen Breyer, Sonia Sotomayor.

A Justice is nominated by the President and is confirmed by the Senate. The Justices are all lawyers and have been Judges in lower courts and often worked ("clerked") for other Justices when they were younger.