Hello. I am a programmer that want to learn some basic artists job. I am good at modelling, but not that good when it comes to texturing. For example… I have a silencer I made and I dont know how to texture it… where to find the texture and so on. When I google, I get a lot nice looking silencers with AWESOME textures in them. I m really stuck at this process and Is the process I hate MOST to be honest. I am looking forward to some tips on how to go through this step ALIVE. Thank you so much for you time and patience 
If you’re looking for a way to speed up the process and aren’t afraid to spend a little money, Allegorithmic have something for you: Substance Painter. There’s also the somewhat pricier 3D Coat, but the Substance tools are great in combination with Unity (and that other engine) because of substances. I recommend their Live package, as you’ll probably like the possibilities Designer gives you.
With physically based rendering you can start by finding metal+colour in SP, then maybe work on it in SD or overlay some sort of partially transparent roughness/grunge pattern for something unique. You can probably get something OK looking for a silencer barrel right out of the box with SP.
For classic texturing you’ll get better advice from an artist 
substance designer is awesome!
but really, you can achieve the same thing in GIMP (although youd have to be more artistically minded i suppose)
overall, my original impression of SD was diminished by realizing you could achieve the same in GIMP … but … really itd take a whole lot more time
( i never used photoshop, and now with their subscription crap i probably never will lol)
http://www.cgtextures.com/ has a huge assortment of free textures
mapzone is free, it came before substance designer … it, relative to SD sucks, but its free and you could do some nice stuff with it…
… whoa what? mapzone’s website doesnt exist anymore…
… well it could only do 512x outputs max… and NOWHERE as good as SD
…hmm… actually i think Blender can do some of the things Substance Painter does… not too sure,
i know it has painting on a 3d model and using a stencil like that…
but yeah substance has the whole “non destructive workflow” thing going for it that really Does save Alot of time