ideas; these should suit either a cadet or a lower decks style game.
Training simulation. As you say; 'welcome to space kids' give them a damage control team with orders from the bridge coming fast and furious... Perhaps leading to a full blown evacuation and abandon ship... Dont drop the 'holodeck simulation' card until the very end when the XO/Department head gives them a performance review and assigns their team.
Anomaly Research. The main ship is called away to an emergency, but the cadets are assigned to a mid level Lt. in a shuttle/runabout to investigate an anomaly. Of course something will happen that they have to face down locally, perhaps an attempted incursion by Romulan spy in an equal powered craft
Diplomatic Relations. A truckulant' diplomat is on board and has made everyones life difficult... This diplomat has been 'assigned' down the rungs and the cadets are given the job with nowhere to delegate any further and so they get to play host to the diplomat during whatever trials the ship itself is going through (this would give them pretty much free-reign of the ship for the duration, along with a narrotor BNPC to push them to be in the right place at the right time, and all you need to know is whats happening outside)
TBH, run all 3 of those and those cadets should be shaping up into promising junior officers with a department assignment, team leader, commendation and perhaps a patron/contact in the diplomatic corps...
DanG/Darth Gurden
The Voice of Reason and Sith Lord
“Putting the FUNK! back into Dysfunctional!”
Coming soon. The USS Ganymede NCC-80107
"Ad astrae per scientia" (To the stars through knowledge)