Setup OpenXR Runtime
if you want to test stardust in flatscreen mode (in a window) without a headset or other OpenXR device, you can skip this step and start with trying out telescope.
Check the hardware table to ensure your hardware and headset are compatible:
SteamVR
You will likely want to use Monado instead, but if you need to the instructions are available.
If you are on NixOS please consult https://lvra.gitlab.io/docs/distros/nixos/ before installing SteamVR.
https://lvra.gitlab.io/docs/steamvr/ is a good starting point, but be aware that the stardust server cannot run as an overlay on top of other games due to SteamVR not implementing the OpenXR Overlay extension.
Monado
If you've got a wired headset, this is generally the way to go.
NixOS
It's generally easiest to follow the instructions at https://lvra.gitlab.io/docs/distros/nixos/ to install properly to the system.
Other distros
Envision is the XR launcher (like a minecraft launcher) of choice for open source XR and is overall better in practice than SteamVR.
Test OpenXR Runtime
Try running XRGears and see if it works, you can get it from the system's package manager often.