Welcome to the void!
First thing to know which is usually a comon mistake, is that smaller = better when beggining. It means less space to fill and looks way more pact in and less empty.

next, the cot job on this guy really isnt good. I rweccomend you go to planetrenders.net and get a few renders from there to use, they are already cut and will help you because i wouldnt reccomend lerning to cut them urself when ur still new to photoshop.

the c4d's are okay, im gald you tried it. They help sigs a lot, but try not to blur them like you did. I reccomend trying a few tutorials closely, and seeing some of the techniques they use. It should help you get ur berrings.