Their job is to help you have fun, be safe, and know your limits. Some camps schedule the entire day so you have an opportunity to try all the different things at camp. At many camps, you'll get to select one or even more activities every day. You can ask about how the day is planned for you. You will make a lot of new friends at camp.
Some campers know each other from past summers and some know each other from school.
Some don't know anyone until camp begins. It's nice to have winter friends and summer friends.