If you get married here, you should not leave the U.S. until you get your green card (unless it's an emergency, and a wedding or a prepaid vacation or something are not considered emergencies). Otherwise, if you leave, you will have to stay outside the U.S. until your immigration process is complete and you get your immigrant visa to return to the U.S. (which could take a year, give or take).
Answered on Jul 17th, 2017 at 2:41 PM