It appears that some new users ask a question before having read just the very basic descriptions about how SO works. As a result their initial post is sometimes downvoted, but the new user may not understand why. Such a bad head start could be avoided if the new user just read about the very basic SO principles before the first post.
The requested feature is that new users start at zero reputation points, and can't make any question or answer posts before having seen the SO pages about very basic principles and having passed a simple test, which will earn them their first reputation point.
Existing users that reads and answers questions are usually very serious about their work on SO, so I think it is reasonable to require that new users invest just a minimum of time in learning about SO before they post anything.
Would that be a useful feature?