spamhole
Welcome to GrapheneOS and Android :-)
My first advice for new user: Dont make your setup too complicated to start out with it can overwhelm and can feel inconvenient. Using GrapheneOS alone greatly improves your Security and Privacy already even if you only use one User Profile with Google Services installed :-)
To start out with dont change much at your setup. Use your GrapheneOS phone like you used your previous phone and just change things to improve privacy and security over time step by step :-)
In your case I would go with two profiles your owner Profile for your private stuff and a work profile for the work stuff :-) I personally would even go with a work provided Phone for the work stuff and keep all work related things off my private devices.
This is just a recommendation from a GrapheneOS user that only has one User Profile with Google Services installed who uses the device only for private things.
For syncing files with your desktop like @"Dumdum" said syncthing is good but if you just want to share one or two files I recommend to look into KDEConnect its a really nice app to connect your Phone to your PC. If your Desktop PC uses Gnome as DE GSConnect is KDEConenct for Gnome.