I am not aware of a shareware version of Final Cut Pro or Final Cut Express.
Can you not return the item to the store and purchase the full version?
Admittedly, the price of Final Cut Pro is expensive for a home-user.
iMovie HD & iDVD do a decent job for most video editing jobs, If you are running OS X they should already be included.
If you are looking for a freeware video editor, Avidemux2 is good. For video encoding, Handbrake and FFmpegX and a few others are up to the task.