Yes, a marriage license is required by law to get married in the State of New Jersey. Also, there is a 72-hour wait. This waiting period does not include weekends, so if you want to get married on a Saturday, you must apply for your license on Tuesday.
Many towns' Vital Statistics offices require you to call for an appointment before applying for a marriage license. Laws can also vary from town to town, so it is important to contact the office where you will be applying to get the most current information.
New Jersey law requires that you bring one witness with you when you apply for a marriage license. You will also need two witnesses to sign your marriage certificate at the ceremony.
Here is the link to find out how to apply for a Marriage license in New Jersey.
https://www.nj.gov/health/vital/registration-vital/marriage-licenses/