A quick run-down of how to use your built-in sequencer:

Press the SEQ button.
Press the TRACK button.
Cursor over to the right to pick your sound.
Press the REC WRITE button. This will start the metronome.
Press START/STOP, and this will give you a 2 measure countoff.
Record your sequence.
Press START/STOP to end recording.
You can then go back and select track 2 and start recording.