Invest in an external microphone. From the sounds of things, you're using the in-built microphone of your camera.
Rode VideoMic: http://www.amazon.co.uk/RODE-ROD-VIDEOMIC/dp/B0007U9SOC
Zoom H1: http://www.amazon.com/Zoom-H1-Portable-Digital-Recorder/dp/B003QKBVYK/
I suggest getting the Zoom H1 over the Zoom H4 to start with, due to the much larger cost of the H4 and the low budget that beginners have to work with. I've heard good things about that microphone though - nice and cheap, and fairly reliable.
Also, a thing to note - the quality between home videos and features is very noticeable. I suggest investing in a DSLR, such as the
Canon 550D, which is half the price of the
Canon 7D and does almost as good a job. That's what I've heard at least, I've not really gotten around to buying a DSLR yet - I'm sure you'll be able to get some fine advice on that in some of the other sections of this forum though.
The script though, I'm not sure what to think about it - I'm not sure if it was a bad script or whether it was simply the presentation, but it just felt like forced comedy. That kind of happens when the actors rely on over-the-top expressions and movement to be funny.
Not sure what else there is to say about it than that. Why there was one section where half the screen was black I have no idea.
The script seemed more appropriate for an on-going series as opposed to a stand alone story - which it may be, I've not had a chance to look at your other videos yet, so I'm not going to criticize it for that.
Still though, your new to this, and it wasn't a half-bad job I guess - the main problems were to do with the technical aspects, and that'll not be a problem once you get into the swing of things. Nor will the way the actors work be detrimental - as you, or whoever's directing, get's better, you'll understand that the way the actors act is as much up to the director as it is to the actor. You can't just expect the actors to act the way you want because you tell them "be funny", but it's a learning process on both sides, so don't worry. The best way to learn is to actually try though, and it's good to see you're doing that. Good luck with your future projects!