It's not a tutorial, but "Docker implemented in around 100 lines of Bash" might help: https://news.ycombinator.com/item?id=33218094

This might be what you're looking for? IIRC it was written for the older cgroup (v1) sysfs interface, so you may need to cross reference it with the cgroup2 documentation

https://ericchiang.github.io/post/containers-from-scratch/

I did one with just the chroot part:

https://earthly.dev/blog/chroot/

Liz Rice has a good talk about the cgroups and namespaces.

https://www.youtube.com/watch?v=_TsSmSu57Zo