There's probably other tutorials out there, and I don't know enough about the specifics of the tutorial to check every conversion, but I would either look for another video, or I would just go for it, and see if you get stuck at any point along the way
While the syntax changed a bit, the overall syntax is pretty similar, although this page documents some of the changes between versions:
https://docs.godotengine.org/en/stable/tutorials/migrating/upgrading_to_godot_4.html
Godot Engine documentation
Should I upgrade to Godot 4?: Before beginning the upgrade process, it's worth thinking about the advantages and disadvantages that upgrading would bring to your project. Advantages of upgrading: A...