While you can still install the Play Store APK, many apps will no longer download or run because they require newer versions of Play Services.

: You must use a version compatible with API Level 19 (Android 4.4). Versions above v23.30.99 generally do not support KitKat. Google Account Manager : Updating this is sometimes required to fix login loops. Android API Levels How to Install/Update Manually

This process is known as "sideloading." It requires no rooting.

File Format: .APK (Note: Android 4.4.4 does not natively support the newer .APKB or "App Bundle" formats without a third-party installer). How to Install the Google Play Store APK

Even with correct installation, you may face issues. Here is how to fix them: