Wait for your score to come in the mail sometime in December. The PSAT is taken in October. Scores are mailed to students as soon as they become available in December.
Log in to your College Board account on the College Board website. If you registered for your PSAT online, then your PSAT score will be available on the website between December of the year you took it and the following February.
Contact the College Board administration directly by either phone or email through the online contact form if you are having trouble logging into your account or you did not receive your score.