For a first video it's not bad. I've definitely seen worse. Although, you could use a few pointers to improve on your next video.
You did a good job pairing up a song and a character. I'm not a DBZ fan but even I could tell that the mood of this song fits with the character. You didn't make the nooby mistake of leaving in subtitles or splattering logos on your video, so points there. The video is pretty clean, visually from what I can tell, but it's on a streaming site, so I can't tell you if you would need to improve. Streaming sites change the quality of the video. If you were to offer a download I might be able to help in that area.
Areas you could improve on:
1. Timing: This is where I think you could use the most improvement. I suggest you listen to the beat of the song and try to time your cuts and internal sync to them. There are many "schools" on sync, and eventually you will have to find your own style, and what you enjoy best, but in any case the timing of the cuts could use a lot of improvement even by the basic standards of sync. Listen to the song, this will give you the ques to your cuts. I find having a few beta testers to point out my sync issues to be a huge help.
2. Lipflap: You want to avoid this as much as possible. The only time I find fair amounts of lipflap acceptable is in romance videos (which your video is not), or in cases where it is very apparent that the movement was left in on purpose. In general lipflap can distract viewers and they end up looking at the mouth moving rather than your video. Lipflap can also come off as badly attempted lipsync.
3. Narrative: I have to admit that I'm not a DBZ fan. I haven't watched the show so a lot of your lyric syncs don't make much sense to me. I can tell you attempted to lyric sync in many places, though. For the most part I see the same guy doing things, but I'm not sure what he's doing. Perhaps in the beats between the song phrases you can set up the scenes a bit more.
Your choruses jump around a lot, perhaps it would make more sense to set each chorus as a series of events, only hitting a few key points in the lyric. Tell me this guy's story and why it's important for me to know about him.
4. Mood/Internal Sync: You have a lot of slow parts to faster parts in the song, then faster parts to slower parts in the song. The visuals should speed up as the song speeds up, and then slow down as the song slows down. This will give your video even more of an emotional sync, as the visuals will be paired with what the audience is hearing. Showing fast movements on a slow part of the song feels awkward, next time put those fast visuals on the fast part of the song. You can really get someone's heart pumping to the action if it's synced to the beat of the song.
Never lipsync for a drama video. Lipsync = comedy for most people. I've seen audiences howl in laughter during a drama video only because of a lipsync. I'm not sure if it was intentional or not, but it appears you have a few spots that look like attempted lipsync.
5. Aspect Ratio: Some of your footage is full screen (4:3) and some of it is wide (16:9). If you really want your video to look uniform and neat you should crop one of your sources to fit the other. How I go about deciding that depends on many factors (was my source originally cropped? do I have more widescreen or fullscreen sources? what is the mood of my video?). However, for this piece, I'd crop it all to widescreen. Wide looks way cooler and more dramatic, and "epic" (like a movie). This song has a fairly "epic" and "dramatic" feel to it. I think that's the aspect ratio that would fit. If you want more information on how to crop your video ask me and I can help you farther.
6. Effects: at 2:20 and 2:40 there is a very odd effect. I'm not sure why it's there. Is that part of the movie? If it's not then the first thing I'd suggest to you about effects is to take a step back and work on a basic AMV before jumping into effects. All the great "Effects" videos put the video source first. At least in my opinion they do. Learn to do a basic video, then jump into effects little by little. Also don't use effects as filler. They should enhance the video, not just show up randomly.
7. Intro: it's fairly long. Most people who watch videos are there to see your video, and probably don't want to wait for it. If you want to have a long set of credits, best to put it at the end imho.
Anyway, not too terrible for a start, you definitely could use some work, but good luck on your next project, and I hope this helps.