Hey, thank you for reaching out about this and offering to help!
Currently, GrapheneOS-specific settings and apps developed by GrapheneOS are in English only.
The project wants to eventually translate those into other languages, but it wants to do it properly with dedicated teams who are organized and can be trusted to provide accurate translations quickly.
Furthermore, preliminary work needs to be done in the code for translations to be properly supported, which hasn't happened yet.
So all in all, the project wants to do it, but it wants to do it properly, which will take time and a substantial amount of resources.