C'mon. Do I really need to write this? Play WHATEVER YOU WANT! Try to learn songs you like, play hi notes, low notes, make funny sounds, play as loud as you can, as soft as you can, songs to annoy others, find out what songs make the neighbors dogs howl (I grew up next door to 6 St. Bernards! No Lie!) Improvise, play the blues. Just play! Anything you do that you can repeat, means you've learned something new about the instrument!