Simulating a transformer in Maxwell 3D "from scratch"

Hello.

I am trying to design a transformer in Maxwell 3D, I cannot find any useful resources online. They all say to import a base model, or start with a model already defined. I need to design my transformer "from scratch" and define my own geometry, wires, everything. How would I go about this? Would I use the data sheets for a given core and then simulate that? Would I have to define the wiring geometry before I could do any simulations to investigate the core losses at my switching frequency?

Thanks