If you need a functioning Google Play Store, upgrade your device to Android 5.0 (Lollipop) or higher.
While you can technically download the APK for free, the Play Store on Android 4.4.2 is effectively broken. Google has disabled server-side support.
Do not install the Play Store. Instead, use F-Droid (open source app store) or Aurora Store (a lightweight client) which still function partially on KitKat. Alternatively, manually download legacy APK versions of specific apps (e.g., Firefox 68, VLC 3.0) from APKMirror.