The simplest disease model is the "Zombie Bite" model. It starts with a bunch of healthy people and one ill person. They all start in random places and move around, but when the ill person meets a healthy person they bite them, giving them the disease. They can then bite other healthy people.
When building a model it is always good to break it down into simple bits you can make sure work. We'll break this simple model down into five bits:
1) Making one person who starts somewhere random.
2) Making that person move randomly.
3) Making lots of people who move around.
5) Experimenting with the model.
Start by clicking on the first link. Make sure you save your work as you go along.