Regarding the SEO add-on, I don’t see that at all. Are you sure this isn’t just happening on your own computer?
Its only happening on the computers with that SEO add-on installed. That’s why I’m curious how to fix that issue. You can see it in the image attached. Basically it pushes down the content… but for some reason the side <div> is not getting pushed down along with the rest.
It’s not moving down because it’s set to position: absolute … which isn’t a great way to do a layout, I have to admit. (I’m not sure why the book goes down that route, but never mind. )
Anyhow, it’s not really a web design issue as such, by the sound of it, because your web visitors are not going to see that. Personally, I’d recommend you dump that add-on anyway, as it doesn’t sound very good. SEO tends to be a pretty dodgy area, I’m afraid. All the same, if you find it useful, perhaps use it in a browser you don’t use often and just view the site normally in your regular browser.
Static is the default, so you wouldn’t need to set it. Just making that Change without doing anything else would not be enough, though. The normal way to create columns is by floating one or both of the columns … But I’d wait till you get to that in your course. That addon is throwing in a red herring that you really don’t need at this stage of your learning.