Is it really evil? Do you really all worship Satan and try to summon demons and what not like some of my other Christian friends have told me. Oh and those friends also told me I shouldn't hang around her. But I really like her so I don't want to listen to them.

No,it's not evil.
Wiccans don't believe in Satan at all,let alone summon him.
It'a good thing you've dropped by,it shows you are moving beyond the bigotry and falsehoods you've been told.How awful that you were expelled just for being who you are.Shameful
You are welcome here,we do not discriminate.Your girlfriend is welcome too,should she wish to come by.
*HUGS* [yay]
http://en.wikipedia.org/wiki/Wicca
click on the blue links,you'll find out a lot more too from these.This is a decent article,but it's not absolute.Your girlfriend may be Eclectic or belong to a tradition or Coven group.Wiccans follow a moral code,much like any other religion and they do not engage in Devil worship or evildoing.Those lies are gross misapropriations,usually perpetrated to breed fear among the 'faithful' of certain Christian demoninations.
I will post some more info for you about Wicca in a bit,but feel free to look around the forums in the interim.We have all sorts of Pagans and Occultists and Christians hereabouts.Yes,you read correctly,Christians.Though not the sort you've been hanging around with,obviously,lol. [thumbup]
We have Satanists too,but they are no more evil than any other person in this World.
The only way to dispel fear like this is through education,we fear what we do not understand and understanding removes the barriers.Rather like homophobia,in fact.
Feel free to ask as many questions as you wish,I am not Wiccan,but I and others here will do our best to answer you,we have Wicca nmembers but I 'm not sure who might be around soonish.I can buzz one of my friends,though, see if he will come by and talk with you. [cool]