Hello, I am 17 years old and just started getting into video editing and stuff can you please tell me how I can improve these movies i know they look real bad lol

http://mamaluke.sytes.net/Videos/AgentBlake2.wmv
http://mamaluke.sytes.net/Videos/AgentBlake3.wmv

Oh yeah and another thing is it possible to do Blue Screen on a older digital camera or does it take away to much color or something? because im about to get into that but those things are expensive so i wanna know first.

Thanks.
Jim