As evident from the name, Materials Modelling (or Computational Materials Science as it is sometimes called) lies at the intersection of materials science and computational engineering. To answer this question, the level of education required depends entirely on what one intends to do with materials modelling.
Materials science is quite interdisciplinary, and it is possible to work on different aspects of materials modelling (like the application of existing models/software to new materials/problems, building new models/software etc.). If one is interested in doing research in the field of materials modelling, typically, it is possible to start participating in research while pursuing an undergraduate degree in a related discipline. So, the undergraduate major could be materials science/engineering itself, physics, chemistry, chemical engineering, mechanical engineering, mathematics, computer science, the list cannot be exhaustive. Also, one can work on a materials modelling problem for their PhD while being officially affiliated to any of these disciplines. So, one often pursues some form of education while already working with materials modelling, and then continues to work in the field.
If the question intended to know of any prerequisites to start doing materials modelling, then the answer could be some understanding of materials behaviour, and the ability to use computational tools to solve problems (which can also be learnt as one starts). The book Introduction to Computational Materials Science by Prof. Richard LeSar is an accessible starting point.