Well for starters if you want something more out-of-the box, just buy a NAS. But what woult be better is to buy a Raspberry Pi 5 and add a micro sd with good amount of storage or maybe some additional external storage and install CasaOS(this is basically a easy UI that allows you to self-host mostly without commands) and install Immich within its App Store, and link it up with your phone(on the Immich app).(If you need any more help DM)