Boom microphone for young filmmaker?

I am 13 years old and I love to make films. I am thinking of buying a microphone on a boom to catch audio, and it would be plugged into an audio mixer, to later be synched with the video. I would have someone holding the boom with the mic on it over the scene. What should I buy to accomplish this? Is there a package that comes with a boom and a mic and a plug and mic clip and all that? Thanks so much!!!!