There are a variety of fancier and bigger ships in that game that you could buy and customize to your disposal. All of this will change the star rating your ship and company has, having more stars gives you a money boost so its best to listen to what the passengers demands are. they tell you that there aren't enough toilets on the ship or there aren't enough places for entertainment. Passengers will rate your ship on what there is to offer for them e.g. This means you can add rooms, pools, food booths and toilets anywhere in the ship.
The first ship you receive as a new player has nothing inside, this is because the game wants you to add rooms and facilities to both your liking and the AI passengers liking.
Mange the money properly or your company will go under (figuratively or literally). you then get money from the trip that you could use to modify and buy newer and bigger ships. The aim of the game is to simply sail your ship with passengers towards any of the several islands in the game.