It's kind of hard concept but it's really just dancing to the rhythm. If you see a lot of bboys who have raw footage (no music over and they're recording with a stereo,) you should see them hitting the "beat" or whatever instrument int he music.
You're only on day 2, so don't fret. You've still got a crapload of time to learn; just try slower songs and you know when you bob your head sometimes when you listen to music? I think that's when you should be hitting the beat with your toprock. It's all about your musicality; just keep it up.
I recommend Def Cut - Fresh; because they rock the bass, and the snare on that one. You can definitely go with it and just try it out. It's a really fun song, too.