Hope you guys have figured this out already, but for those who haven't, the auto shutdown menu only appears after you've started the print from the SD card (to me at least), as in starting the print from the machine and not the cloud app. After you start the print, you can tap on the section where the nozzle temp, bed temp, speed, and Z offset settings are displayed and a new menu should appear with the auto-shutdown function. The auto-shutdown option is not available if you print over the Creality Cloud app.
Also, another useful tip is the bed wobbles when it's in the middle, to fix this, I've loosened the allen key bolts that holds the rails down, there's 6 bolts in total. Re-tighten the bolts again, not too tight, and the rails will flex outwards slightly, ridding you of the bed wobble. Tightening the wheel that holds the nozzle housing is needed as well. Hope this helps! First time 3d printer owner here and my prints have been awesome, super happy with the CR-10 Smart 