Enterprise infrastructure has been moving to containers for years because of scale and redundancy. Spinning up new VMs for every app failover is bloat and wasteful if it is able to be put in a container.
To really use them well, like everything in IT, understanding the underlying tech can be essential.
Honestly, if you want small and cheap get a raspberry pi to play around or rent a VM.
If you care about storage too you can get a Synology NAS (pricy) which is pretty newbie proof and comes out of the box with different and photo sync along with support for VMs or docker.
It can but it's the server hardware that decides your performance, you can just avoid transcoder on the fly and have h264 mp4 and can run JF on a toaster smoothly.
No love for kubernetes?