I’m quite new to Unreal and I’m wondering how to change that Unreal default Character’s ‘skin’/texture? It is blue by default so should I drag some sort of texture on it?
Hey
Either through Material Override (Static Mesh Actors in Unreal Engine | Unreal Engine Documentation go to the Material Override part)
Or directly in the Static Mesh Editor Static Mesh Editor UI in Unreal Engine | Unreal Engine Documentation
Best
Hey thanks mate, but I’m trying to edit the Character’s skin therefore, where can I find different skins/textures so that I can follow up on those links you gave me 
You know what I mean, the head, legs, etc.
Ah the materials directly. Well the easiest way if you don’t know where they are you can just click on your Character and than you have in the Details Pan the different Materials, where you than can double click on.
Just as a addition. What you had on Static Meshes are Materials consisting of Textures but by far more different operations to create interesting Shaders. So if you want to dig in a bit deeper into how to use the Materials Editor I can again just point to the excellent documentation: Unreal Engine Materials | Unreal Engine Documentation
Next to that I can recommend you first to go through some of the excellent Editor introduction which gives you the basics.
Level Editor
Materials
Blueprint