Valem on YouTube - Several "bit-sized" tutorials introducing essential VR concepts in a concise way for Unity and Ocuslus (Rift/Quest).
Summary: create a bowling game; hands; grab; teleport; etc.
Unity and Oculus - Getting started guide - This is a great tutorial (takes a couple of minutes). Really, simple and easy to get + VR. Summary: create a floor and four walls. A sphere as player. Add physics to the sphere. Add a bit of easy to understand code to the player. Turn on VR (Edit >> Project Settings >> XR Plugin Management, Edit >> Project Settings >> Player >> XR Settings).