Deleting paterns

Hey there everyone.

Got myself a po-16 today and I am a complete noob in producing/creating any music at all. I’m having one issue.
Without any input from my side, if I press the play button, I can hear some random pattern sounds.
I can add my own “stuff”, but I can’t delete the ones already preset.
Is this just the way its supposed to be?

Press Key+Pattern to delete your Pattern and start from scratch.
Have a read at the manual, it’s quicker to get such info.