There are two ways you can get the layout code and preview. The first one is there are two buttons in the screenshot saying "preview this layout", click 1.0 or 2.0 whichever myspace version you are using. The other method is, when you scroll down you will see links of layout styles (such as default, skinny, etc.) You can choose whatever style you may like, just click on a link and it will give you the preview and codes. P.S. This is only an example layout.
Once you get on the preview, you will need to scroll down to see instructions and codes. Please follow the instructions carefully to make the codes work properly.
But, I have no idea which myspace version I should use. Help!
If you signed up from April 2009, you automatically gets profile 2.0 and you should always use 2.0 layouts. If you signed up before that, you are using 1.0 version unless you upgraded to 2.0.