Unity is a powerful game engine. It is a tool that allows you combine 3D models (made in a separate app) and code (from Visual Studio, auto installed) to create games, tools, and worlds. To work in VR, you need the XR SDK (or Software Development Kit). Unity is currently developing it's XR SDK. Information and processes are subject to major changes, so be sure to check the dates and the software version being used before committing to any tutorial.
Rift, Quest, Vive & Cardboard are all different and require different approaches and settings. Furthering that difference are different platforms as in Mac, PC, or Android, and differences in controllers, Vive is more wand-like, Rift are sometimes called knuckle controllers, and Cardboard devices may lack any controller - even a single button.
The best path forward to find a simple tutorial that fits your initial interests on a website that hosts a library of tutorials that may be linked to create a larger overall project. When it comes to programming, be careful not to assume that combining different parts of tutorials from different websites will work. To new users, its recommended to avoid using the Unity Store. There are a large number of potentially useful blocks of code and/or models called packages there, but using them (and knowing what you are really buying) is an intermediate level skill.
Below are a number of good and as of Spring 2020 fairly recent tutorial channels.
Unity Learn - The company website, it's always up-to-date. It's a big site with lots of information, but it can be hard to find what you need.
Unity Manual - The company manual, its the single most complete guide out there. Learning how make use of it is one of your tasks.
VR with Andrew Look for Unity XR Toolkit to learn about VR. This is a great place to start when leaping to a project.
Code Monkey - A lot of basic tutorials and a lot of complete game tutorials
Jimmy Vegas - He's got of ton of work, basic stuff to full games. Often very specific and maybe specific to your needs.
Free Unity Tutorials - A number of 2D & mobile games. Useful, but not VR
Brackeys - RPG and others, but tutorials are +2 years old. Useful, but not a great place to start.