GrapheneOS only works with the GOOGLE PHONES. I do not recommend this at all.
There are many people like myself who provide services for non-techies, providing a brand new phone with something nice and clean like LineageOS which can be tweaked to be just like Graphene. So they get the finished product right away. This is the direction we should be encouraging people to go and then bring to learn how to do it on their own going forward.
Or they can stick with iOS and play with "privacy" apps lol