https://training.play-with-kubernetes.com/

https://professionallinuxusersgroup.github.io/course-books/lac/u9intro/ — this course I like quite a lot, it’s very in depth about Linux overall, covering containers and kubernetes.

There is also this site: https://killercoda.com/ , which has online interactive environments and tutorials.

For example: https://killercoda.com/het-tanis/course/Kubernetes-Labs

I use syncing through Mozilla’s servers. Part of what killed my motivation for a self hosted setup was realizing that Mozilla sync is e2ee.

Firefox sync is end to end encrypted by the way: https://support.mozilla.org/en-US/kb/sync

It is technically also self hostable, but I gave up when I was investigating. Hosting the sync server itself wasn’t too bad, but I couldn’t figure out how to also self host the account server, which is also needed to have the sync process entirely based on my own infrastructure.

Sovereign OS is pointed out to be source available only in the comments.

GrapheneOS replies to many of the addressed points, and notes that SovereignOS is actually really just a fork that seems to charge for some bs features and preinstalled apps.