Unfortunately, Google Play services has stopped?
Naturally, you cannot simply install Playstore as user app. First, it needs to be a system app, and second it depends on several other Google apps (GSF, Google Services Framework – see Wikipedia). For details, please check with our google-play-store tag-wiki and especially follow up to How can I install the Google Apps Package (Play Store, …) on my Android device?

Alternatively, you could e.g. use the the YalpStore app (and optionally the microG framework, an open-source GSF alternative – not really needed by YalpStore but would provide the needed services for other apps usually depending on GSF).