Is there something we need to do to officially enter the contest, like filling a form? Or, all we need to do is submitting our entries by the deadline.

I sent out the response on the main thread. The community benefits most when there is active discussion of issues and challenges the entrants are facing on this channel so even though it is not required we do strongly encourage participation, posting and helping others. The goal is to both assess and also to advance the state of the art in AI generated silicon design.