Welcome to the Cryosphere! The Cryosphere is a government owned space station used as a trading post and military base in the Music System (see info starmap). There are regular shuttles from the station to other places within the system both civilian and military. (See info ships).
You are a raw recruit in the Royal Navy. Your eventual aim is to reach Commander - to accomplish this you must complete missions in order to progress through the ranks from Junior Cadet (the ranks you entered at) to Commander (see ranks). These missions include solving puzzles, neutralising enemies of the United Kingdom, and earning credits in order to buy better equipment, medicine, clothing, etc.
Your first priority should be to complete simulations in order to gain valuable skills in combat, puzzle-solving, mobile-interaction, and familiarity with the game. These training simulations are played out in the simulator rooms - to use one, obtain a simulator crystal from the Simulator Shop (they are free to cadets), and take it to a simulator, then insert it in the slot - the simulation will then begin (see info simulators). These simulations may also be useful if later in the game you want to improve or refresh your skills.
The final simulation is 'Academy'. Upon completion you will graduate from the Academy and become a crewman, ready to start performing missions in the game proper.