This is a procedural moss shader created in blender that works with Cycles and Eevee. It's just as simple as drop the shader between your principled BSDF and material output and you have a beautiful customizable moss shader ready to render!

If you want this shader to be in all you other project, you need to save the project as a startup file. to do this you need to go to:

File_Defaults_Save Startup File