Ok, well the PHP code should pretty much be the last thing you need to concentrate on for now. You need to come up with a list of well-defined objectives (the link between two pages is not a well-defined objective by any means) - you need to know exactly what you want your code to do before you even think about writing it.
At first, don't apply this to a university webpage - apply the idea to a collection of pages which you know an expected outcome. Then try and design an algorithm to accomplish that outcome.
The algorithm could be just drawn up with pen and paper - or if you're pretty comfortable with PHP just do it in code. Once you come up with that algorithm, then is time to ask about how you would do these specific things with PHP.
Just a note. Generally in University the marks are not just awarded for code. A lot of the marks often get awarded for careful planning and a well-thought-out system.