[Q] Help, no OS!

long story short- I got a HTC one M7 (sprint?) And i'm stuck in twrp!
Everything's wiped, no OS and its not rooted. The TWRP recovery pops up but i have no idea what to do.
I'm super stupid with phones so if someone can walk me through this it would be much appreciated.

Details;
+TAMPERED+
+UNLOCKED+
m7_WLS PVT SHIP S-ON RH
HBOOT-1.44.0000
RADIO-1.00.20.0626
OpenDSP-v31.120.274.0617
eMMC-boot
jul 5 2013,17:19:22:-1

from xda-developers http://ift.tt/2cUpvmK
via IFTTT