Need help with shaders materials n textures

Please excuse me, I am new here. Reaching out to see if anyone can help me.
Its a little difficult to explain what I know and don’t know.
Guess I can say I use cycles render

I need help with textures n shaders for
1)scales
2)chitin
3)human skin
As in what to do to get the best results for these without (as in the case with scales) modeling on a microscopic level

>x<
Not sure if I am in the right place.
I probably should say I am very good at making 3d models, just not so good at colourings n texturings