Oh I see. You mean like v3.0.1 will be stable, and v3.1.0 will be stable. Yeah that’s true. But v3 (as in v3.0.0) is breaking. At least that’s how I have always seen the terms used.

No, v3 is a release with breaking changes:

This release includes several breaking changes; read the full migration guide here. It’s worth mentioning that many of the breaking changes are updates to API endpoints and only affect third-party tools that integrate with Immich’s API. For the vast majority of users, updating works exactly as it always has.

https://immich.app/blog/v3.0.0-release

That’s why the major version was increased, it implies breaking changes in semantic versioning, which Immich is doing since v2 apparently:

Given a version number MAJOR.MINOR.PATCH, increment the:

1. MAJOR version when you make incompatible API changes
2. MINOR version when you add functionality in a backward compatible manner
3. PATCH version when you make backward compatible bug fixes

https://semver.org/

Well if you want the real basics of self-hosting then depending on your level of knowledge you may want to follow a Linux tutorial like this one: https://labex.io/linuxjourney

This will teach a lot of basic knowledge and terminology you may need when setting up or maintaining containers and VMs. Admittedly, this is somewhat tangential knowledge to your immediate goals, but if you want to actually use your self-hosted stuff remotely later this will become critical to doing so safely.

As for the map, for me it was something like:

Local LXC/QEMU → Remote LXD over SSH on a RPi → Proxmox on a dedicated box through the webinterface

In hindsight I would have started with Proxmox directly though I guess. One big downside is it doesn’t integrate well with Docker containers, you have to set up a full VM as your Docker host. On the upside though you can install LXC containers from https://www.turnkeylinux.org/ in a few clicks, so it’s very good for just testing stuff out and playing around.