As of writing I am currently making a comprehensive video tutorial series on how to create your first VRChat World using a Unity-only workflow, which includes best practices and optimization.
This is a project-based course which will end with you having a made a unique room and understanding the basics of world creation, such as using Unity and the VRChat SDK, constructing unique geometry with Probuilder, materials and PBR textures, lighting and lightmapping, the asset store and external models and prefabs, World Space UI, Udon, pickupabbles, and Quest compatibility.
The full series is here: Create Your First VRChat World - YouTube
