Okay firstly I am trying to use the search engine Dogpile but when I search for anything it comes up with no results. The next is about plugins I have flip4mac as well as silverlight and I can't add the plugins even if I use the file on my computer it say's its corrupted.
It is heavily recommended against adding any plugins or extensions to the TorBrowser.
Extensions might alter the behavior of the browser so that you can be fingerprinted. They might even send data to some server, that even though it is send over Tor, could identify you.
Plugins, like Flash and Silverlight are not aware of Tor and therefore bypass Tor. Even if they would send all traffic over Tor they can be turned into spies by telling a website about your system and this includes your real IP address.