Default [Q] escape teamwin on lg g2 back to factory

Hi all,

I just recived my sprint lg g2, i was asked whether to update the system to the sprint network, being a mistake i clicked yes. Im in new zealand so i thought it wouldnt matter. Bad mistake and it took me to the twrp menu... I simply wanted to restore the phone back to factory settings or just return to how it was before. (I had no idea that twpr was installed on ge phone to begin with)

However i cant seem to figure it out. Ive backed it up not that that really matters, but when i go to reboot system it says

"your device does not appear to be rooted, install supersu now? This will root your device".

I swipe and it reboots simply back to twrp... How do i escape this?

Thank you so much