You cannot uninstall Google Play on an android phone. It's part of the Android system. You may have removed it from the home screen. You can look or search for it in the app drawer under "Play Store" and then add it back to your home screen.
If you can't find it, make sure it's still installed by going to settings/apps and looking for Google Play Store. If it shows there, it's still installed. Again, YOU CANNOT UNINSTALL GOOGLE PLAY without rooting your phone. If, for some reason it is *not* there, you should factory reset your phone and restore your backup. This should put your operating system back to normal.
