Do I need to loose weight/exercise? Thanks?

okay I'm 13 and I'm 5'6 and I weigh 120-123. I'm a dancer but cles don't happen during the summer so I don't get very much exercise. I do this acting camp/cl for part of the summer but that's over. I'm going to a camp in a few weeks for a week that has swimming, tubing, volley ball, rock climbing walls, ect.. But lately I've been staying up until 1 or 2 in the morning and getting up around noon. I do care about my weight, but that's because I have to be healthy. Like with my family genes and history, if I get overweight I like will get diabetes. So, I usually wear a size 3-5 in pants and small for junior tops(I'm a 34A ugh) so do I seem like I need to worry about my weight? Or do I need to do some exercising? Cuz this is my only time of year to sleep and be lazy and stuff cuz when school starts I'm in AP cles and I have to keep straight a's, I have dance five days a week and acting three days(2 after school and one at our comunity theatre) oh yeah also I only eat when I'm hungry so if I'm not hungry for lunch later I might just have like some guacamole or something. And I know it's bad but I don't eat breakfast cuz I've been sleeping past it. Advice?