Amateur Radio is a licensed service that is used for non-commercial/non-profit radio communications for individuals that share a common interest in radio communication for both personal hobby and educational use.
To receive a radio communications license on this radio service you will need to pass a licensing exam administered by Volunteer Examination Coordinators acting as a liaison on behalf of the FCC. These exams are usually administered by a local Amateur Radio Clubs.
The following websites will assist you with studying and finding a testing session.
HAMSTUDY – Use this site to study for your exam.
ARRL – Use this site to locate an examination session.