No in-person interview, you just file for visa online, and at the end of your online application you schedule your biometrics appointment and get that done within 2 weeks. They just scan your hands and take a photo. Then you send off all your documents to whichever office you are applying to.
As for the marriage license, it depends on which state you are in. We were married in Texas, and you were allowed to get the license up to 30 days before the ceremony, but at least 72 hours before the ceremony. He will have to go with you for that. You can just google marriage license info for the state you plan to marry in. Good Luck!