I'm a novice myself, infact kind of the opposite of you; I'm shit at modeling but I like setting up nice looking scenes with other people's models.
What you need to understand is that a good looking render is made up of:
3) Render settings
5) Composition (although this is more for a SCENE rather than an object)
So that means you NEED an HDRi (or BLACK world setting), a lighting system (start with 3 point, it's easy and looks great), good materials as the default materials suck dick (Cynicatpro's got some great looking free custom materials, you get get them for free from his site or you can download them off blendswap).
You NEED a proper lighting setup: Light creates shadow, shadow creates visual interest, and reflective / metallic materials need light or else they'll look like GARBAGE.
Render settings are a bit trickier but not nearly as important as you're thinking; proper settings here let you use fewer samples and let the samples calculate faster and with less noise, but if the scene (lights and materials) are shit, no render setting tweaks are going to make a difference.
Compositing is its own art form, a shit render (i.e. too dark, too drab, whatever) CAN be fixed here with color correction, with painting over, with different film emulation settings, and so on, but again if there's nothing for the Compositor to work with because you didn't set up any lights and shit, then it can't do miracles (besides the miraculous shit like creating fog where there was none by overlaying a fog image onto your render, or creating glare, or gently blurring certain surfaces to get rid of noise).
TL;DR: You need to do some of the longer tutorials on cgpersia for Blender and you need to read the articles on Lighting on CGShrimp.
Gleb Alexandrov is a blender god (but he sucks as a teacher, so don't get upset if at first you don't understand what's going on).