I have come across hundreds of great, however unprofessionally written questions that have many downvotes just because the member is new, and did not write the question in the 'proper format.
Unless you were the one casting those votes, you have no idea why those votes were cast. Only the person who cast those votes knows precisely why they voted on the post.
That said, votes are there to reflect the quality of the post. Posts aren't downvoted because the author is new, they're downvoted because the post is bad. New users are simply more likely to make bad posts, so you may well notice that posts from newer users are more likely to have a lower score.
As far as editing goes, at the end of the day, it's the question author's responsibility to write a good question, and to fix the problems that it has. You're more than welcome to help them out and edit the quesiton if you want, but you certainly aren't obligated to.
If you do choose to edit the post, then as far as how you should vote on it; you should vote on it based on whether or not the post is useful or not useful, just like any vote you ever cast. If you think the question isn't a useful question after editing it, you should downvote it; if you think it's useful, you should upvote it. That said, you should really avoid editing questions that are still going to be bad questions even after you finish editing them (simply because you're wasting your time).
You absolutely shouldn't vote on a post just because of how others have voted. You should vote on the post based on whether or not you think it's useful, regardless of whether other people felt it was useful or not.