Hello Rieghs! Welcome to Cubebrush 
I'm really liking the work you've posted so far. The rendering on the two portraits looks really nice., although the second one could maybe have used a bit more work on the hairs (but this might just have been a practice piece, so that's not a big deal)
Your last piece though, I really love it. It's a fairly simple composition of a guy doing something mundane, and yet it feels so unnerving to me. It's just like you caught the character doing something he shouldn't be doing, but he's just watering a plant. Great job on that one!
Also, you mentionned wanting to become a concept artist. Well concept art is more about doing iterations after iterations of the the same idea to arrive at the ''perfect'' design. And while your first piece kind of work as a concept, the others strike me to be more illustration based. Now neither illustration or concept art is better than the other, so you can chose to do either one. I just thought I'd mention that, from what you've posted, you seem to be going more into the illustration route.
Once again, welcome and keep up the good work!
