I wouldn't concentrate on trying to make a masterpiece when getting the hang of it. Just figure out the kind of thing you'd like to make and have a crack at, say a cool chase, or a big fight or whatever. That's probably the best way to work out all the camera stuff and sound editing etc. It's worth watching the editing and framing on real life movies and TV programs very closely too, for things such as the rule of thirds, and not crossing the camera line etc. Paying attention to stuff like that makes things easier to edit.
When you've sussed that, it's up to you. Whenever I make anything with it, the only criteria is: 'What do I think would be cool and a challenge?', for example, that Nam movie I just posted had two goals...
First I wanted to edit aeroplanes, guns and explosions to fit the period's music as much as possible, whilst avoiding the cliche Doors and Jefferson Airplane tracks that are always in Nam movies, so, almost like a pop video. Which means you'll notice things like when the
Beach Boys sing
'And we've never missed yet with the girls that we meet' in
I Get Around, it's at that point that the US soldiers are aiming at some Viet Cong girls, and the explosion from the napalm with the slo-motion 'Sam Peckinpah-style' deaths is timed with the lyric
'When I die and they lay me to rest' from
Norman Greenbaum's Spirit in the Sky, also look out for repeating motifs such as a body being hurled in the air to the 'spirit in the sky' lyric, which also refers to the petroleum spirit of the napalm explosion
'going up to the sky' etc, which also could refer to the aircraft too. There's a lot of references like that in it.
Second, because war is sort of visually cool, but in reality is in fact a nasty business, I wanted it to make a big mood shift from 'wow yeah guns and bombs are cool' to being 'slightly disturbing' in the fact that many people die in wars in a horrible way and in fact a few of them that are killed in that movie of mine are actually unarmed, including a woman, which hopefully jars quite a bit against the music and appears a bit shocking.
Whatever you end up making, I'm sure you'll have fun with it.
Chock