I'm a noob with zero knowledge of the subject. Materials Modeling is so specialized that it's not even on Wikipedia yet. Help orient a newcomer. What do you use it for? Can you use it to model materials for a bulletproof t-shirt, a superior mask to protect against COVID-19, a flux capacitor?
I'm just as curious of a user here as you, but I was able to find that a Materials Modeling Wikipedia page does in fact exist. :)
Computational materials science and engineering uses modeling, simulation, theory, and informatics to understand materials. Main goals include discovering new materials, determining material behavior and mechanisms, explaining experiments, and exploring materials theories. It is analogous to computational chemistry and computational biology as an increasingly important subfield of materials science.
Answering your last questions: yes, yes and yes.
One thing to consider is which approach do you want/need to use. You can use an atomistic approach where you simulate/model the properties and the material starting from the atomic structure of it (an input file with the list of atoms and its coordinates). The other approach is to use your material as a continuous medium and use its mechanical and optical experimental properties.