Actually, your second question may have defined it for you. If you've never worked with a database before, then no, it's not "simple". It involves learning...oh...say the first 10 to 15 chapters of a typical ASP.NET tutorial book (or equivalent).
It's not *hard*, as such things go. But it does involve a *lot* of concepts. Client/server interactions, designing pages in Visual Studio, creating a properly normalized database, connecting your ASP.NET code to that database, retrieving and adding data. That feels like the important parts.
One thing I would certainly suggest: If you are just starting out, don't get involved with the old old version of ASP.NET that this forum is for. Move on to the latest version. If you haven't done so already, go download Visual Web Developer Express from Micro$lop (http://msdn.microsoft.com/express
will be a starting point). Read, especially, the tutorial material on that site.
I would say that, for an *experienced* ASP.NET developer, developing a DB-based quiz system, complete with (say) user registration and scoring and reporting is the work of a couple of days. Less if they already have some of the framework sitting around ready to use (and many will). I would say that if you have never used ASP.NET before, then maybe 4 to 8 weeks of moderately intensive part time study *might* get you there.