I want to learn to render to make games or renders as a hobby but i dont know where to start.
As the other said, trial and error.
Of course, there's tutorials, there's probably even online classes, but creating 3D Computer Graphics is both something technical and artistic. The technical part can be taught (what is a diffuse map, how to configure a good deep of field, etc.), but it's not what will make your creations good looking. Once you know all this, that are basically the same for all 3D render engines (only the names sometimes change), you'll still not be able to do something at least average.
It's your eyes, and so your experience, that will tell you what you need to do to correct this badly defined texture, find the most natural pose for this character, and all.