My first impression is that you have some fairly decent stuff and you seem to have some of the low poly basics down. "Don't waste UV space, don't go nuts on triangle count, ect..." but overall there is a lot to work on. The site itself. The overall layout is cluttered with a lot of mostly useless info right up front. That…
Actually I think behance is like the biggest site where you can find commercial art in graphic design / architectural previsualizations or advertising, plus it's backed by Adobe now. I would definitely not call it amateurish, but it might not be ideal to showcase real-time art (you're mostly limited by image size)