That’s a pretty wide age range, but I’d say in general, if the content needs to be seen as a unit and can’t really work as standalone videos, you can trend towards longer episodes and just release them all at once so interested audiences can just binge. No sense in breaking it up into lots of episodes if it all needs to link together to be enjoyed anyways.
If the individual segments don’t need to be seen together, you might want to try shorter episodes, because people are more likely to commit to a standalone thing they stumble on if it’s quick. If they like it, they’ll keep watching and find the rest of the episodes. With shorter episodes you’ll be able to promote things individually, and a single episode taking off in popularity will raise the views and audience for the rest. For instance, my recent series has episodes all under 3 minutes long, and one in particular has been more popular than the others, which has then led to all the episodes getting more views as people come for the popular one (episode 8, in this case) and then check out what else we have to offer.