There is at least one district courts in every state. California has four district courts. The judges for the district courts are appointed by the President and must be approved by the Senate. There are no qualifications for becoming a judge, except that one must be an American citizen. Most judges are lawyers who are able to understand the law.
Judges serve lifetime terms.
There are approximately 565 judges that serve the district courts, with at lest one judge in every court. The District Court is only the first of three federal courts. The courts of appeals is the second level in the federal court system. All of its cases come from the district courts, but only certain cases are heard. Usually it is a case where a mistake was made in the process of the trial.