Chaperone policy 2pm or 4pm

Hey guys! I’m going to carowinds on opening day and I was wondering if the time to be there without a chaperone is 2 or 4. My friends and I are all 15 so I’m not sure what it is because I’ve seen 4 pm some places and 2 pm in others. Also, will the park be very crowded? I’ve never gone on opening day but I assume it will be. Thanks!