It depends on the ship and length of cruise. the smaller/older ships tend to do 10-day cruises, They will get older passengers and afr fewer kids.
7-day cruises on the R-class and and newer ships will get plenty of younger people. HAL will never be Carnival or NCL, but I still love their cruises because the food & service are outstanding, the crews are very well trained and not over-bearing, and they have beautiful cabins and rarely encounter any problems.
Just relax and enjoy the ship and the ports.
HALs private island is outstanding as well, with sting rays, horseback riding, snorkel & scuba diving.