You have a device with a custom ROM. It's already unlocked and rooted, so you need to restore it to stock. Follow this guide:
http://forums.androidcentral.com/nex...e-restore.html
But download and install the latest factory image from the site. If you don't understand that process then read through the thread to understand the process before attempting.
The ROM You have doesn't have the Play Store by default. You need to load it manually (a file called gapps).
Sent from my Nexus 5 using AC Forums mobile app