In that example, he isn't using a shopping cart program, he's just adding Paypal buttons to some product pages he added to his blog. I guess you can do that, but you won't get the features available in Zencart.
No, you can't install Zencart in a bloggggspot account (the forum here won't allow the name without the extra 'g's). You'll need an actual domain of your own (www. mynrose.org, for example) to install Zencart.



