Every model rocket has certain basic features. A rocket has a system of fins to keep it on track, it has an engine to give it power. It has a recovery system, and and a nose cone.
Every rocket has some type of recovery system and a nose cone to reduce the drag.
There are certain factors that affect the performance of a rocket. Model rocketeers keep all of them in mind as they construct a kit. The greater the impulse from the engine the higher the rocket will go. Engines are available in a variety of powers, burntimes and delay times. The first engine usually a lower power engine is recommended so you can test the stability and get the feel for what the rocket is going to do.