I think it would be a good idea to start with a wip thread in the projects forum and show some screen shots. This allows you to learn from critics and suggestions.

A good level should not be just a collection of models in a large room with default light. This community can help you to improve your design if you are a beginner. Well, there may be some bad comments from one or two users, but on the other hand you cannot improve without critics.

About the level upload. The timeline ends in about 6 months from now. Once we know how large the compressed levels + assets are, I will decide how the files find their way to the jury.
If there are only small levels, they could be delivered per email. You could provide a download link, etc.

It is not defined, yet.