how do I get Google Play back I need help re-installing Google Play 

I don't know how to. I have tried turning off my phone, but it doesn't work. I want to download Temple Run 2, but I can't because I don't have Google Play. I am hopeless.
Because you don't have Google play it is safe to assume that you are rooted. In this case you can just flash a "gapps" package from the internet.

Or, you could also install Google Play from the internet (via downloading the .apk)
It should auto update if its not the latest version.
You can find an .apk here:
http://www.apkmirror.com/apk/google-inc/google-play-services/

You may also be able to install Google Play Services from the Play Store.
Link: https://play.google.com/store/apps/details?id=com.google.android.gms&amp;hl=en