A:  The woman named Lilith has actually been around before even Judaism.  She was first present in the myths of Sumeria, and is noted in a few of the texts there.  In Hebrew myth, she was the first wife of Adam, and in some versions, the wife of Satan, and even helped in the temptation of Adam and Eve. She was only directly mentioned in the bible once, in Isiah somewhere I think.  More directly to the question, Cain's wife is never certain, and actually a very debated topic.  In the bible, there were two tribes in the beginning of genesis, the tribe of Seth and the tribe of Cain. Cain's tribe bred the wicked people of the world, and Seth's tribe resulted in the birth of Noah.  This sort of goes along with the legend of Lilith, as she bred demon children.  So in context, it Lilith could have been Cain's wife, but it never actually says this.
 
 

Q:  What does the tree of sephiroth have to do with anything? why did it show up in end of eva?

A:  The Tree of Sephiroth is the path to God.  It is symolic in that the path is formed by Eva-01, so that through it as a conduit, we would obtain Instumentality.
 
 

Q:  Who came from Lilith and who came from Adam?

A:  In myth and religion, the Lilim came from Lilith, and Adam bore both the line of Cain and the line of Seth.  In the story, humans came from Lilith, and Angels came from Adam (supposedly)