If youre oing to do this joakim heres a few things you need to think about before starting the game.
What engine will you use?
Will it be OW like Zelda or will it be corridor like fable?
What polycount will be the max for various objects and characters?
What system requirements do you want the game to have?(goes hand to hand with the previous question)
Will it be windows specific or multi platform?
How do you want to start?
What language will you use?
To make it easier on you, blender has an intergrated game engine, and you would use python(you will learn python in school since youre gonna learn maya)
If you want to use another engine, this is said to be "easy to use"JMonkeyEngine
This is in no way meant to discourage you, you just need to be sure that this is not an easy task and theres alot to do even before beginning the game itself.
Theres alot more to think about, be sure to read up on this. And as i said i wont help with modelling unless its ok with your teacher, but i can help in other ways, like if you have any questions i might be able to answer them.