You can follow this steps:
1.You need to enable “Unknown Sources” option on your phone,going to Settings -> Security -> Unknown Sources,find the Unknown Sources option and check the box,this means now you can install apps from sources outside of the Play Store.
2.Install APKPure app on your Android Phone.(You can download many kinds of games and apps with APKPure app on your Android devices.)Using the browser on your computer,go to APKPure to download APKPure app,you can also download Google Play Store APK and trasfer the APK to your phone.
3. Connect your Android phone to your computer with a USB cable and copy APKPure app to your Android Phone.
4.Open the APKPure app on your phone and search Google Play Store in the search box,click the install button bellow and wait for a while you'll get the latest verison of Google Play Store app.
Google Play Store app has been updated to version 6.9.15,you'll always get the latest version with APKPure app,you'll get a notification immedately once the google play store has a new version.