There is no such thing as a reset button on our blogs and there is no content in the blog linked to above. When you delete the Hello World placeholder post you get a 404 (page not found) error on the front page of the blog. http://en.support.wordpress.com/not-found/
Not to worry because as soon as you publish a post, not a page it will disappear. http://en.support.wordpress.com/post-vs-page/
I see you are using Imbalance 2. Imbalance 2 offers two layout options, fluid and fixed.
Fluid means the width changes according to screen resolution (or the width of browser) your visitors use.
Fixed means the width does not change according to screen resolution (or the width of browser) your visitors use.
Column one is the blog title and tagline; you edit them in Settings > General.
Columns two and three are for two menus; you create and load them in Appearance > Menus - instructions here: http://en.support.wordpress.com/menus/
Here’s a link to a custom menu walkthrough > http://onecoolsitebloggingtips.com/2011/08/11/wordpress-com-custom-menu-walk-through/
There are many common errors, misunderstanding and misconceptions when creating custom menus and you can read about them here > http://wpbtips.wordpress.com/2011/12/19/custom-menus/
Column four is for widgets; you add them in Appearance > Widgets.
You need to set a featured image in each post in order to see the thumbnail in imbalance 2. Click on the module that has 'featured image' in it (if you don't see the module, look at the top of the editor window for 'screen options' and check it') then the image editor will appear. Browse to the image you want to use, via that, in the usual way, and then when you've found it, click the 'featured image' and when it appears in the module (outside the edit box) just close the image editor, and save your post as usual. An image that works best with featured images at least 210 wide.