The cadets are probably going to be from different years at the academy, so most will be twenty-somethings, not teens, plus a few older instructor characters to round out the cast. The setting presumably the 32nd century Federation HQ/Starfleet Academy starbase and the characters will undoubtedly have a training ship of some kind, which they'll take out most episodes to have the usual Trek hijinks.
So overall it will probably have a similar feel to early DS9, where there were some young officers and a couple grizzled veterans residing on a space station with little ships they take out to have the usual Trek hijinks.
So overall it will probably have a similar feel to early DS9, where there were some young officers and a couple grizzled veterans residing on a space station with little ships they take out to have the usual Trek hijinks.