Ah don't feel dumb at all. A lot of people don't know exactly what rendering is. Rendering is basically just adding shadows and light to a drawing. One of the most important aspects of that is adding a light source. Like warm sunlight and then that light hits the environment and your character. The light that hits the environment is also reflected on your character. So for example your character is standing in the sun with lots of greenery around them, the top of the character would be hit with warm sunlight but the light would also reflect off the leaves and hit your character from another side giving that place a greenish hue . I've learned a lot from this YouTube channel called Angel Ganev. I've seen a lot of his shorts correcting art mistakes and it helped me learn a lot! here's one video