The tags and categories appear in the sidebar.

Thanks.

Another thing we can do is look at the demo site for a theme to try to help. Here is the demo site for Koi:
http://koidemo.wordpress.com/

To hide the search bar for the Koi theme based on the demo blog, you can add the following to your Appearance → Custom Design → CSS editor:

#header form {
	display: none;
}

If you need help getting started with custom CSS, check out this linke first:
http://en.support.wordpress.com/editing-css/

If you have created Pages that are not displaying in the horizontal menu bar I suggest you go to > Dashboard > Pages > All Pages and hover over the Page titles then click "edit" and check the page visibility settings in the Publish module.
edit pages screen http://en.support.wordpress.com/pages/edit-pages-screen/

Troubleshooting – My Pages aren’t appearing
They must be public pages – not private.
Public – The page will be visible to everyone.
Protected – The page is protected with a password you set. Only people who have the password can view a protected page.
Private – Pages are only visible to blog Editors and Administrators. Private pages are not visible in Reader, feeds, or in any search. A page can be private without being password protected.

If you created a custom menu http://en.support.wordpress.com/menus/ then you can add Pages to it http://en.support.wordpress.com/menus/#adding-pages

#content {
	width: 752px;
}

#content .hentry.post {
	width: 645px;
}

#sidebar {
	width: 166px;
}

One of the form buttons doesn't adjust automatically, so you can use this to force it:

.widget input[type="submit"] {
	max-width: 100%;
}

And the Facebook widget is a little tougher, you can control the overall width of it, but you can't target the things inside it because the core elements inside that widget are controlled by Facebook directly. Trying to decrease the width of the Facebook like container doesn't really look too great, so you might want to leave it expanded. Here is an example of making it smaller:

.widget_facebook_likebox iframe {
	max-width: 100%;
}

It looks like you need to click "Remove Background" on the Appearance -> Background panel in your Dashboard. Also, ensure you clear the background color that is set -- open the color picker and click the "Clear" button. That should trigger the theme to restore the original graphics, like new.

Since this is an older topic, I'm going to mark it as resolved and close it. However, if you're still having this problem after trying the above steps, please don't hesitate to post a new thread and we'll be happy to take a look. Thanks!

I'm sorry that it took us so long to respond to your question. Does the error still occur for you?