Some1Somewhere Have Sandboxed Google Play Services and Framework downloaded
Play Store is the other app that's needed by some apps since as the usage guide says, it provides services used by apps:
The Play Store provides many services used by apps including Play Asset Delivery, Play Feature Delivery, in-app purchases and license checks for paid apps. You can use sandboxed Google Play without the Play Store but many apps won't work correctly without it. The Play Store app is also the most secure way to install and update apps from the Play Store. Installing it is highly recommended for general purpose usage but you can install only GSF or only GSF/GMS if you know it's all you need for what you want to use.
After installing Google Play, Play services needs to be initialized. Our recommended approach is to open the Play Store, press the sign in button and wait for the sign in page to load. Once the sign in page is loaded, it means Play services is finished initializing. You can leave the app without signing into an account. Signing into a Google account is only required if you want to use features depending on being signed into an account. For example, some apps use Google account authentication instead of their accounts having a username and password. The Play Store requires being signed into an account in order to install apps or use in-app purchases. This is still true even for an alternate frontend to the Play Store. Aurora Store still requires an account but fetches shared account credentials from Aurora Store's service by default.
That's likely why it's not working for you. You have an incomplete installation of Play services. Make sure to reinstall the apps needing Play after you complete the setup.