After the death of Abel, Adam and Eve had another son, Seth.
Genesis 4:25 And Adam knew his wife again, and she bore a son and called his name Seth, for she said, "God has appointed for me another child instead of Abel, for Cain slew him."
However, over the course of their lifetimes, Adam and Eve had other sons and daughters besides Cain, Abel, and Seth.
Genesis 5:4 The days of Adam after he became the father of Seth were eight hundred years; and he had other sons and daughters.
I hope you have found this helpful.