Just FYI, there are a lot of hoax websites that will pop up a scary-looking message telling you that you've been infected. Then, they'll give you some fake contact information, you'll contact them, and they'll try to convince you to do something that ultimately will allow them to screw you. They can be very, very tricky, but believe me: no legitimate business operates that way.
Here's how you deal with those kinds of things: close the tab in your web browser that the scary page is on. If you only have one tab open, open another and close the bad one. If that doesn't work, close your web browser (Opera, Firefox, Chrome, or whatever you use to get on the internet). If you open it again and you get the same message, you need to change your homepage to something normal, like startpage.com.
Don't ever, every contact those people–they're lying. If you're really, really worried, take a picture of the message and the web page address, then call Apple and ask them about it.
Hope that helps, and welcome to the internet–you'll get used to it in no time :)