theneobob one we do not advise, condone or support downloading apps from places like apkpure.
If you had read and followed the instructions and documentation here:
https://grapheneos.org/usage#sandboxed-google-play-installation
You can open our app repository client (Apps) and install the 3 core Google Play apps mirrored in our repository. Our app repository client has support for dependency installation so you can simply directly install the Play Store and it will install GSF and then GMS as dependencies.
You will note that you should open the 'Apps' app from the app drawer and then tap Play Store followed by Install which will install ALL of the required elements to get Play Services to work.
Lastly you NEED to at least tap Sign In to initialise them. You can then download the apps you want from Aurora Store OR log in with a throwaway account/personal account to use the actual Play Store itself.
Please make an effort to familiarise yourself with the Usage and FAQ sections of grapheneos.org