I think discouraging newbies is a bad idea - we were all newbies once. If I'd faced a test before being allowed my first post I'd probably have gone away (and never known enough to regret that choice).
Perhaps showing a newbie a short sample question before they proceed to their own might help. Most people would probably dismiss it with a click (do you read all the licenses you accept) but a few would linger enough to learn something useful.
Or provide a (link to) a template to edit (put your mwe here ...).
