Victor, do you want to be a professional designer? Or do you just want to have fun and post some renders? I think some clarity regarding your intent might help guide the conversation.
If you want to become a professional designer, there are plenty of us on these boards who are glad to help with feedback and advice. This is a pretty encouraging community that is happy to have more talent in the field.
If you just want to post renderings, that is fine as well, but you will likely get few comments.