Without verification, you could be installing a Trojan that steals your Google credentials or uses your device for a botnet.
Download a compatible from APKMirror (verified as well). Install it following the same steps as above. Troubleshooting Common Android 4.2.2 Issues android 422 google play store apk verified
If using APKMirror, look for the "Verified safe to install" badge, which confirms the certificate matches Google's official signing key. How to Install the APK on Android 4.2.2 Without verification, you could be installing a Trojan