After Effects is the wrong tool, it's not an editing application. You haven't specified anything about your footage, your Operating System or your computer hardware, so it's hard to provide you a specific answer.
Premiere Pro is Adobe's editing software. Chances are, if you have After Effects you may also have Premiere Pro installed.
But most computers have simple editing software built in: iMovie on a Mac, or Windows Movie Maker on Windows. There are other free editing applications available on both platforms - just Google for free video editing software and you'll find examples.
ahh thx i'm using window 7 and a xps 17 with a dame good viddeo card, though thank you for teh advice i will check out google.
As has been mentioned, you should use Premiere, or pretty much any other video editing application to edit video. After Effects is not a video editing program.
That being said, a simple edit like what you described shouldn't be too difficult. Once you get it done, simply import your AE project into the Adobe Media Encoder and use the YouTube presets there to create your final video.