Most likely a group interview looking at enthusiasm for the job and maturity. Then the head of the camp will interview individually asking question like your availability and obviously some quick interview questions like why do you want the job.

It took around 30 minutes. They were looking for engaged energetic people to hire for their camp. The questions were basic questions and all staff were very nice. The interview took place at the camp itself and was a one-on-one interview for only one day. There was no further interview after the first one. They usually tell you if they want you right after your interview.