I also applied to CSUN around the beginning of January and just completed my group interview as well.
They contacted me the first week in February for my interview.
I'll tell you about the group interview because I'm sure you want to know
6-8 people, I had 8.
Every one introduces themselves
Everyone is then given a question pertaining the social work (not a personal question) and has to answer it on the spot
Complete a group activity
Then answer a 'why have you chosen social work' type of question
Everything is completed in the group environment
Hope that helps!