hi, how long does it take for a new guy to receive commissary?

Commissary is once a week. It typically takes one week before the newer inmates can get commissary. But it is more related to the "day of the week they are designated", for instance if they come into the institution on a Wednesday and the commissary day for him is on Tuesday, then he'll be able to go the next Tuesday. Also, money in their account must be there in advance.