Some very basic shader tutorials?

Unity Shader Programming: Beginners to Advanced Techniques

Shader Development using Unity

Immersed With Shaders Refabricated

Edi’s Shaders 1.20, 1.19.4 → 1.18.2 — Shaders Mods

Shader Effects - Color Theory - Awwwards

[Released] 2D Effects Creator - Node-Based 2D Shader Effect Creation Tool