The genealogy of Cain is given briefly in Genesis 4:17-24. However, this was not the line that led from Adam to Noah, and all other lines of descendants were destroyed in the flood – including Cain’s descendants.
The genealogy of Adam goes through his son Seth to Noah (Genesis 5:3-32) and this is the part of the family tree that matters in the story of good and evil. In general, the Bible gives many more genealogical details of righteous people than of evil people like Cain.