我是EB1b主申请人，USCIS sent me an I-797 appointment notice to get finger print done next week. (1)I wonder whether my hu*****and and kid will get their own I-797 for their finger prints or not. (2)Do I need to call local office to confirm the appointment before I go there according to the assigned date? (3) My code is 3, what does that mean? Thanks!