Hi, a 3D artist should be capable to generate models on request, should have own style and personality about it. Also capability of spotting what is missing in scene and making it look better.

C++ is a good choice for gamedev.

Though in your other posts I've seen that you are looking to join new team for your first jam. I'd recommend sticking with newer teams for start. Even if you are able to learn fast, understand that I'm not able of teaching fast.

Good luck.