The blog linked to your username is a free blog being free hosted by WordPress.com. Please read this entry very carefully.
WordPress.com vs. WordPress.org
WordPress.com is a hosted blog service. You do not have to download software, pay for hosting or manage a web server. WordPress.com does not permit uploading themes or plugins. WordPress.org is free software. You can install themes and plugins, run ads, and edit the database. Check out our article on the differences.http://support.wordpress.com/com-vs-org/
1. The following applies to your WordPress.com free hosted blog:.
comments default settings > Discussion > http://en.support.wordpress.com/settings/discussion-settings/
enable and disable comments on any post or page > http://en.support.wordpress.com/enable-disable-comments/
2. Using WordPress to Create a Website > http://en.support.wordpress.com/using-wordpress-to-create-a-website/
3. There is no FTP access to free hosted WordPress.com blogs and we cannot upload plugins or theme into them.
4. My comment here is focused on display in the horizontal menu of your blog. What’s critical is to understand when creating a website structure is the following:
1. The differences between pages and posts > http://en.support.wordpress.com/post-vs-page/
2. There is only one dynamic page in a blog for posts and we cannot post to more than that one page. When we publish a post it automatically appears on the running page for posts and also on the Categories pages and Archives pages.
3. We organize our posts by assigning Categories to them. Although there is only one dynamic page in a blog for posts and we cannot post to more than that one page, we can create the appearance we have done so by creating a custom menu. In that custom menu you will be displaying Categories in tabs along the horizontal navigation to achieve what you want.
These are the how-to instructions:
A. You create a custom menu. http://en.support.wordpress.com/menus/
B. You add the Categories you want to display and arrange them in the order you want.
C. Then you add and drop and drag the sub-categories below the appropriate Categories, and when you have everything arranged in the menu that you want you save the menu.
D. Go to the “theme location” module at upper left on the menu page. Select your custom menu name from the pull-down labeled “primary location.” Click the save button in that module.
Note: If you wish you can also include pages and sub-pages of your own choice and custom links in your custom menu as well.