there is different methods and schemes based on your problem in discretization of equation .you can solve it via finite difference or finite volume or finite element . I think the best sources for learning how to discrete your equations are CFD by klaus A. hoffman and also CFD by john Anderson . you can get too many information , for example using FTCS method or Richardson method for discretizing parabolic equations.
Matlab is a general programming environment where you can do what you want, FD, FV, FE, SM, SE or other CFD methods. See for example https://www.mathworks.com/support/books/finite-volume-method-in-computational-fluid-dynamics.html.
Furthermore, you could also exploit the pdetool to solve more simple model, for example potential flows.
In CFD, the choose of discretization techniques depends on the specific governing equation used in your case (for example, compressible flow or incompressible flow), mesh type (structured or unstructured), type of flux term (for viscous flow, the discretization of viscous flux is need, and usually different from the discretization for the convective flux), and the order of accuracy you want to reach.
Of course, on top of those things I just mentioned, there are basically three different type of discretization techniques in numerical methods: finite difference, finite element, and finite volume, as explained by previous answers.
In my opinion, the Finite Volume is the main stream in the field of CFD. Besides the books recomnended by Pejman Shojaee, I also strongly recommend the book by J. Blazek: "Computational Fluid Dynamics, Principles and Applications", it has 3rd edition now, and it focuses on the finite volume technique, and covers everything in detail involved in CFD. My labmates and I reference this book a lot in our research work.
Matlab is a programming software. You can write codes as what you want and feel free to program. There are many discretization tools such as finite element method, finite difference method, finite volume method and so on about which there are many books and papers you can refer to. They all are the mature method and have the complete system. Hope this will help you, and good luck to you!