I just went through some tutorials a couple of months ago and had some good luck with this series by Valem on Youtube[1]. It's from 2020 and a bit outdated in a couple parts (like I think the input system changed in more recent Unity versions, but you can select the old version, it just has different names, and also I think some of the links for the controller assets were broken somehow, but I was able to download a package that had them I think), so read the comments near the top, which show timestamps and where things might be different now, but overall I was able to get things working fine in my Quest 2 device.

I was also looking for books, and the Unity 2020 Virtual Reality Projects Book[2] looks promising, and I just got a used copy (still being sent to me). Again since it's from 2020 there might be a couple things out of date, but it looks like it could be worth it.

I use Unity in Windows so I can't help on the Linux front.

Good luck! You can ping me if you get stuck somewhere, I might have had the same issue and might be able to help you get unstuck.

[1]: https://www.youtube.com/watch?v=gGYtahQjmWQ

[2]: https://www.amazon.com/Unity-2020-Virtual-Reality-Projects/d...