Introverted means: shy, reserved, withdrawn, reticent, diffident, retiring, quiet, timid, timorous, meek, bashful, unsociable.
Why would you want to be "...more introverted at sports camp?"
I think you mean extroverted. I am an introvert by nature. But I learned to get over some of my shyness and timidity. I knew that I wanted to play volleyball. I went to a volleyball camp as well, and did not know anyone. I was a freshman at the time. So being on the low totem pole, being a guy (not a girl) that went to volleyball camp, I was probably 1 out of only 5 or 8 guys there. The rest were girls. I was very very timid, and very shy. But the coaches and teachers were great. They made sure everyone had chances to practice/play/drill and learn. It was definitely the best summer I have had. Being an intro tho, I didn't make any real friends. I did meet some cool people (we didn't have internet/social media/smart phones let alone cell phones back in that time frame). Probably around 30+ years ago.
Anyway just do the best you can. The other thing to consider is that you are new to the people there. And people don't know how you are or how you will be. Volleyball camp for me was a week long 5 days. It was great. 2 days might be a little short. Understand that a lot of people will be just like you coming in knowing no one. Just be as open to learning about them as well as teaching them about yourself. But most importantly is to learn the game! Volleyball is a great sport. Don't worry about what people will think about you. You go to a camp to learn how to play. As long as you are enjoying the learning and the playing, then you will do fine.