Zac is Cain's father.
We do not know who the first man born to Adam was. We only know that Cain is the first one mentioned in the Bible - but this may have been mainly because of Cain's significance as the first murderer.
Grendel being descended from Cain in the epic poem "Beowulf" highlights his monstrous and evil nature, as Cain was known for committing the first murder in the Bible. This connection reinforces the theme of good versus evil in the poem and adds depth to Grendel's character as a symbol of chaos and destruction.
Ace Cain's birth name is Horace Truman Cain.
Lynn Cain's birth name is Lynn Dwight Cain.
Sam Cain's birth name is Sam Wayne Cain.
Haven Cain's birth name is Haven Jude Cain.
Krisinda Cain's birth name is Krisinda Jeanette Cain.
Lamont Cain's birth name is LaMont Terome Cain.
Erin Cain's birth name is Erin Elizabeth Cain.
Cain was born first, followed by Abel. They were not twins; Cain was the firstborn and Abel was his younger brother.
If you are referring to Cain in the book of Genesis then nothing. Cain and Noel did not directly interact to my knowledge.