Doing pinball simulations is actually pretty difficult. A year ago I would have said that it isn't *that* difficult, but now I can look at it from a different angle.
You have to understand vectors, planes, how to detect collison against various shapes(*), how to devide the space in spatial areas (for reducing the amount of collision checks), how to resolve a collision (eg projection), how to respond to collision, what an integrator is, and how to use em.
(* since it's about a ball colliding with something you can actually just check for point collisions against "fattened" shapes - however calculating this "fatting" isn't that easy, if you don't already know the math)
And that's just a short overview of the logical problems, which you'll have to solve; things you'll need to learn. And there are most likely other things which you would also need to learn for actually finishing that project.
So, as a first (somewhat bigger) game it's a pretty bad choice. If you can spend a lot of time on that project, you would still need at least 6 months for creating a usable/robust simulation (without anything else like graphics/sound/media).
Really. I mean it
Megabytes of articles to be read, dozens of little try-out-testing programms to be written... so many things you've to understand before you have all pieces for that puzzle. Sounds scary? Well, it is... but you can learn all those things in little steps, by reading an article about physics, programming a little simple game, testing things, writing a different little game (with another focus) and so on.
Well, I guess it's worth to keep making a pinball game as a long term-ish goal.
A rather ugly but informative page:http://personal.myvine.com/~pinball/html/physics/pinballphysics.html
I'd played several pinball machines, but I hadn't noticed (back then) that they use "knockers" for producing a allmighty "THWACK!" sound. It's also pretty interesting to read how bumpers etc work