The final thing you will need is a place to launch the rocket. Most school playgrounds are large enough that this isn't a problem. The minimum size is approximately the area of a football field. Obviously, the larger the field, the better the chance of recovering the rocket. Launching rockets is one of the least inexpensive hobbies to get into.
Kit cost are also very affordable, averaging less than eight dollars.
If your school funds are limited, it is possible for the students to work in groups, thereby even lowering the cost of the activity. Rocketry is best used as the attention getting device, and to enhance whatever else you are teaching. So in reality, all you need to know is how to follow the simple instructions on how to build and launch the model rocket. These very simple instructions are contained with each rocket kit. Beyond this, you can easily and quickly learn whatever your interests in rocketry are.