These are just some basic classes that all Cadets must take. As for the RPG aspect of it, just know that you will know how to do this stuff and play out any of the classes you want.

Administration, Weapons: Phasers, Unarmed Combat, Computer Operation, Computer Programming, Sensor Operations: Sensors, Transporter Operations, First Aid, History: Federation, Language: (Federation Standard), Language: (any non-native), Law: Federation, Mathematics, Physics, Pilot: Shuttlecraft, Starfleet Protocol, Vacc Suit Operations, Xenobiology: General, Xenology: General, Zero-G Operations