There are all sort of defaults set when you first create a Wordpress blog. One of the standard plugins that we all tend to install is the Wordpress Stats plugin which places a tiny smiley image in the footer of your blog unless you or the theme you choose to use, takes steps to remove it.
Placing code samples effectively into a Wordpress Post can be tricky, that is until you start using the fabulous Wordpress Plugin Syntax Highlighter Evolved. Without it, the HTML of the post and the HTML of the code excerpt can become entangled. There are quite a few settings available on the plugin and it may be a case of trial and error to see what works best for you. This video explains more.