I would say don't delete either, as both have handy apps/services that can enhance user experience on your Samaung device 😎. For instance, Good Lock is only a available on the Galaxy Store, whereas the Google Play Store has many apps that the Galaxy Store does not have. I believe either store is not detrimental to your device, if you keep both of them, so just have fun with the apps and features available is all I can say 😉. Hope this helps! 😃