We’ve helped to compile a list of useful trajectory & other flight performance and analysis tools for you. Among the most popular are Open Rocket, RASAero, & Space Cad. Some of these tools are free. Others require purchase. Before you go and spend money on programs, we recommend you give Open Rocket a try. The software is open source which means that many people can contribute to its improvement.
Open Rocket Tutorial Video
These videos from youtube (courtesy or PennCharterChemistry) will help you learn how to use Open Rocket features to design and simulate a rocket flight.