Hello I'm trying to make some kind of tool for an school website, what I need to do is to make students take a test and according to what are the results (27 posibilities) they get a set of activities (questions) according to their level which they can solve in around 3 months logging periodically to the website, plus I need teachers to log and look at the reports.

Now, I'm a graphic designer myself so my skills are mostly html5 and css3 and I know some php (edit existing ones only) and javascript (jquery) as well, most people tell me that I need a CMS to do the tool but all I find is CMS for display like blogs or news websites which I think aren't useful for me because the website is already made in html and css3 only (I need to add an extra page for the tool)

I understand I need to create users and give them special rights according to what type of user they are and I also understand that I need a database where I can store all my questions.

What is the best way to do this? what do you suggest me?

Thanks