You should be in the editing stage of your movie project. If you don't want to use iMovie, there are some option without having to spend money. You can download a number of different editing programs in a "trial" basis. The trial versions are usually fully functional and will work for 30 days after installation. Below are some links to the more popular programs and most are available for Mac or PC. Make sure you select the right one for your system:
AVID: Avid creates the programs that are often used in Hollywood. Their basic versions would be good for this project: AVID DS or AVID Media Composer.
ADOBE PREMIERE PRO CS6: This is a very powerful program; big learning curve though. This is a free trial.
VEGAS MOVIE STUDIO: Sony has several versions of its movie-making software--all available for a free trial.
AVS VIDEO EDITOR: Basic program
POWER DIRECTOR 11: A basic video editing program.
Here is a FREE program (shareware) that can be used as well:
Wondershare Video Editor
Also, checkout CNET for more programs.