If you've learned the riffs, now it's time to play along with the backing track!
Since the the first part of the song is just guitar, you'll just be playing along with the high hat counts. After 4 counts, you'll hear an open high hat. Right when you hear that open high hat, that's where you'll begin the first riff.
If you make a recording of yourself playing along, be sure to post it in the forums to show off your skills! We'd love to hear it.