Let's address the second question first. All now website start with no PageRank. It is also probably not indexed. See Check if your website is indexed and how to get it indexed. For those who are in a hurry, see Fastest way to get indexed by search engine.
Your website may also be black listed by search for practicing Black Hat SEO (Search Engine Optimization) such as making text invisible by making the font color same as background.
A blogger complained his blog's PageRank has been downgraded to unranked. There can be various reasons why a website's PageRank may be downgraded. One of them is what they call the "Google Dance". Google changes its algorithm and some websites may get their PageRank increased, some downgraded, some downgraded very badly. I am not aware of anything we can do about this, unless you know the inner workings of Google search engines which they will NEVER reveal.
Or perhaps, you can. Check Google Webmaster Guidelines and see if you are complying with their guidelines.
After ensuring your website complies with their guidelines, if you don't already have a Google sitemap for your website, add Google sitemap (click BACK button to get back to this page) to your website, then go to Google Webmaster Tools, click "request reconsideration", select "request reconsideration", select the website if you have more than one, submit request, then pray hard.
Recently, I read that Google has downgraded blogs which participate in "Pay per post" to ZERO (0). I heard too that those who have Text Link Ads on their websites got their PageRank downgraded.
NOTE: Some sites recommend adding rel="nofollow" attribute to the <a> hyperlink tag that someone paid you to add to your blog, and then asking for reconsideration. This will probably work. Each person have their own views about what is right and wrong, but my view is that if someone paid you to put that link and you add that rel="nofollow" attribute to get your PageRank up again, I think one should inform the person who paid for the link and see if they agree or have some feedback. But of course don't take this as me telling you what you should do.