You need to keep studying PHP before you'd even be able to use the code to do this if someone gave it to you.
Firstly, you will be working with .php files, unless your webserver is configured to pass .html files through the php parser (which is unlikely). Secondly, it sounds like you just want frames or something anyways (which is non php related).
There are php ways of doing it, though and you will want to look at the include() function to get an idea of how that works.
Really, though, I think you should get a grasp on the hello world basics before jumping into something like this.