There are so many aspects of 3D that you need to learn that it can be overwhelming.
For example there is lighting and all the subgroups to the different lights and shadows, and IMO its one of the most important and over looked aspects of 3D.
Then there is modeling and good topology and loop flow, using quads and not tries, the subgroups to that, hard surface modeling vs subdivision/hypernurb modeling.
There is procedural materials and understanding how to create complex materials within your material editor/tree understanding index of refraction for glass and water. Understanding HDRI for good reflections and gi rendering.
There is texturing and the subgroups to that, UV unwrapping, painting, sculpting, baking and so on.
Then there is understanding your rendering engine, and all the work behind good rendering i.e.. GI, Ambient occlusion, DOF, physical renders vs standard renders and so on.
Then there is rigging, skinning, animating, dynamics, hair, partical systems and on and on.
To start with just learning to navigate the interface of maya and what everything is and does is a daunting task if you have never used it before let alone used any 3D app. And lastly the overall principles of 3D and 3D space.
My friend I think you are going to be in for a rude awakening. And if you promised to take on a job involving maya I hope you are going to give it 100% and just know that you are in for a long up hill battle.
Like I said before it can take people years to get a truly full understanding of 3D and Maya.
best of luck.