hi i am new here and i wanted to ask if someone can recommend on any good tutorial how to texture human body in blender(more realistic)?
Hi and Welcome,
That’s a big question… !!! 
Is this going to depend first on how much “knowledge” you have of BLENDER?
- Do you already have a body model of a character?
- Are you comfortable with UV unfolding?
- Do you have a good understanding of shaders?
IMHO you should start doing some research from tutorials on Youtube…
… to visualize several of them in order to better understand the different steps.
In short, try by yourself and if you have difficulties, come back to the Forum to explain the problems/incomprehensions you encounter… 
okey so i can handle my self when it comes to modeling it’s far from perfect but the mesh looks okey i also know how to use uv on objects(many times they are flat).but when it comes to human or animal texturing its diffrent because you will have different veriation of skin in different parts on the body .
i have some basic understanding in shaders .
lets say i find that texture is it possible to make realistic human if i unrap it and how to do that?
another question is it possible to make realistic skin just from shaders and not by that kind of textures?
I’m not an expert on the subject… but it’s perfectly possible…
Some interesting links (some with the example files):
Realistic skin material using the 2.8 Principled BSDF (with File on the site of CGBlender.com)
… search directly in the Forum (Skin shader) … there are a lot of solutions …
Hoping this might help you out a little bit. 
thanks!! 